850+ Adjectives That Start With "O" – Meaning, Synonyms & Examples

Adjectives are the heart of expressive language, adding vibrancy, clarity, and dimension to communication. They elevate simple statements into rich and captivating narratives. Adjectives starting with the letter "O" often convey notions of optimism, openness, originality, and outstanding qualities, making your writing more impactful and memorable.

This page serves as your comprehensive resource for discovering adjectives that begin with "O." Whether you're a writer crafting imaginative stories, a student improving your essays, or a language enthusiast seeking to expand your descriptive vocabulary, you'll find inspiration and practical tools to enhance your communication here.

To streamline your exploration, we've organized adjectives starting with "O" into easy-to-navigate categories. Each section features detailed definitions, synonymous expressions, and real-life usage examples. With a curated collection of over 800 "O" adjectives, this guide is designed to spark creativity, refine your linguistic skills, and empower you to express yourself with confidence and precision.

Positive Adjectives Starting with "O"

Positive adjectives starting with "O" embody qualities such as openness, optimism, and originality. Whether you're describing an outstanding achievement, celebrating an open-minded perspective, or highlighting an optimistic outlook, these words infuse warmth and positivity into your language. Adjectives like outgoing, opportune, and openhearted demonstrate versatility and creativity, while terms such as overjoyed and outspoken add emotional depth and significance to your writing.

Incorporating positive adjectives that start with "O" into your communication can elevate its impact by inspiring encouragement and authenticity. Whether you're crafting motivational content, heartfelt messages, or captivating narratives, these adjectives help foster a deeper connection with your audience. Words like optimistic, outstanding, and open-minded bring vibrancy, sincerity, and originality to your writing. Embrace these "O" adjectives to inspire hope, foster meaningful connections, and leave a lasting impression.

For a broader range of Positive Adjectives, don’t forget to explore our Comprehensive List of Positive Adjectives

Additionally, you can expand your vocabulary further by checking out our Comprehensive List of Adjectives Starting with "O".

Adjective	Meaning	Synonyms
Optimistic	Having a positive outlook on life or situations	Hopeful, positive, confident
Outstanding	Exceptionally good or impressive	Excellent, remarkable, extraordinary
Open-minded	Willing to consider new ideas and perspectives	Receptive, flexible, broad-minded
Opulent	Demonstrating great wealth or luxury	Luxurious, lavish, affluent
Outgoing	Friendly and socially confident	Extroverted, sociable, affable
Orderly	Organized and neat in arrangement	Neat, systematic, tidy
Observant	Quick to notice and attentive	Perceptive, alert, attentive
Outstanding	Exceptionally good in a particular field	Exceptional, notable, brilliant
Openhearted	Kind, generous, and sincere	Kindhearted, generous, compassionate
Optimistic	Confident about the future or success	Positive, hopeful, sanguine
Overjoyed	Extremely happy or delighted	Elated, thrilled, euphoric
Objective	Impartial and unbiased	Fair, neutral, balanced
Organized	Systematically arranged or efficient	Orderly, systematic, methodical
Original	Innovative and unique	Creative, inventive, novel
Outstandingly	Exceptionally or remarkably good	Impressively, notably, remarkably
Opportune	Occurring at the perfect moment	Timely, well-timed, convenient
Obliging	Willing to help or assist	Helpful, accommodating, cooperative
Optimized	Made as effective as possible	Enhanced, improved, refined
Orderly	Neat and organized	Tidy, methodical, systematic
Open	Not closed or locked; receptive to ideas	Accessible, available, welcoming

Negative Adjectives Starting with "O"

Negative adjectives starting with "O" are essential for describing challenges, flaws, or nuanced emotions in your writing. Whether you're illustrating an overbearing character, an oppressive atmosphere, or an obstinate mindset, these words bring depth and tension to your narratives. Adjectives like offensive, overcritical, and obnoxious effectively convey struggles or shortcomings, while terms such as ominous and outlandish add complexity to stories involving conflict or uncertainty.

Employing negative adjectives that start with "O" can intensify the emotional impact and realism of your writing. Whether you're crafting flawed characters, portraying moments of adversity, or building dramatic tension, these adjectives allow you to express struggles and emotions with accuracy and depth. Explore our comprehensive collection of negative adjectives starting with "O" to expand your vocabulary and infuse your storytelling with layers of complexity and authenticity.

For a broader range of Nagative Adjectives, don’t forget to explore our Comprehensive List of Negative Adjectives

Additionally, you can expand your vocabulary further by checking out our Comprehensive List of Adjectives Starting with "O"

Adjective	Meaning	Synonyms
Obnoxious	Extremely unpleasant or offensive	Annoying, repugnant, offensive
Obstinate	Stubbornly refusing to change one's opinion	Stubborn, inflexible, unyielding
Offensive	Causing someone to feel deeply hurt or upset	Insulting, disrespectful, hurtful
Oppressive	Weighing heavily on the mind or spirit	Repressive, tyrannical, burdensome
Overcritical	Excessively critical or judgmental	Judgmental, fault-finding, hypercritical
Overbearing	Unpleasantly overpowering	Domineering, authoritarian, bossy
Obsessive	Excessively preoccupied with something	Compulsive, fixated, fanatical
Opaque	Not transparent; hard to understand	Obscure, unclear, ambiguous
Outrageous	Shockingly bad or excessive	Scandalous, egregious, appalling
Overwhelming	Too much to handle or manage	Crushing, overpowering, unbearable
Outdated	No longer useful or relevant	Obsolete, old-fashioned, antiquated
Ominous	Giving the impression of something bad to come	Threatening, foreboding, menacing
Oblivious	Not aware of or concerned about what is happening	Unaware, heedless, inattentive
Overindulgent	Excessively indulgent or lenient	Permissive, lenient, excessive
Outlandish	Strange or bizarre	Weird, eccentric, unconventional
Opposed	In conflict or disagreement with	Resistant, antagonistic, averse
Overconfident	Excessively confident	Arrogant, presumptuous, cocky
Oversensitive	Excessively sensitive to criticism or stimuli	Touchy, thin-skinned, easily offended
Obstructive	Causing a blockage or hindrance	Blocking, hindering, impeding
Off-putting	Unpleasant or disconcerting	Unappealing, unsettling, disconcerting

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Descriptive Adjectives Starting with "O"

Descriptive adjectives starting with "O" bring vibrancy, clarity, and originality to your writing. Whether you're portraying an opulent setting, describing an outgoing character, or crafting an optimally structured argument, these words enhance your language with vivid imagery and emotional depth. Adjectives like outstanding, ominous, and openhearted add texture and uniqueness, ensuring your narrative captures the reader's attention.

Incorporating descriptive adjectives that start with "O" allows you to communicate with creativity, precision, and depth. Whether you're weaving a compelling story, composing an analytical essay, or delivering an engaging presentation, these adjectives help you captivate your audience. Discover our carefully curated collection of descriptive adjectives starting with "O" to expand your vocabulary and enhance the expressiveness and impact of your writing.

For a broader range of Descriptive Adjectives, don’t forget to explore our Comprehensive List of Descriptive Adjectives

Additionally, you can expand your vocabulary further by checking out our Comprehensive List of Adjectives Starting with "O".

Adjective	Meaning	Synonyms
Opulent	Characterized by luxury and wealth	Lavish, affluent, rich
Opaque	Not transparent or hard to understand	Obscure, cloudy, unclear
Outstanding	Exceptionally good or impressive	Remarkable, excellent, extraordinary
Optimistic	Hopeful and confident about the future	Positive, hopeful, sanguine
Overwhelming	Very great in amount or intensity	Overpowering, intense, immense
Obstinate	Stubbornly refusing to change one’s opinion	Stubborn, inflexible, unyielding
Observant	Quick to notice things	Perceptive, attentive, alert
Orderly	Neatly and systematically arranged	Organized, tidy, methodical
Original	New and innovative	Creative, unique, novel
Opportune	Happening at a suitable time	Timely, well-timed, convenient
Outlandish	Strange or bizarre	Eccentric, weird, unconventional
Open	Receptive to new ideas	Accessible, welcoming, available
Offbeat	Unconventional and unusual	Quirky, unique, eccentric
Outgoing	Friendly and socially confident	Sociable, extroverted, affable
Overjoyed	Extremely happy	Elated, euphoric, thrilled
Overbearing	Unpleasantly overpowering	Domineering, bossy, authoritarian
Optimized	Made as effective as possible	Enhanced, improved, refined
Ominous	Giving the impression of something bad to come	Threatening, foreboding, menacing
Oblivious	Not aware of what is happening	Unaware, inattentive, heedless
Overconfident	Excessively confident	Arrogant, presumptuous, cocky

Emotional Adjectives Starting with "O"

Emotional adjectives starting with "O" are invaluable for expressing the intricate and profound layers of human emotions with authenticity and clarity. Whether you're describing someone as overjoyed by success, overwhelmed by emotions, or optimistic about the future, these words convey a diverse range of feelings. Adjectives like offended, outspoken, and obstinate add depth and nuance, enhancing the emotional resonance of your writing.

Leveraging emotional adjectives that start with "O" allows you to articulate complex emotional experiences with creativity and precision. Whether you're crafting an evocative story, developing multi-dimensional characters, or delivering a powerful message, these adjectives help establish a profound connection with your audience. Explore our curated collection of emotional adjectives starting with "O" to enrich your vocabulary and infuse your writing with heartfelt emotional depth.

For a broader range of Emotional Adjectives, don’t forget to explore our Comprehensive List of Emotional Adjectives

Additionally, you can expand your vocabulary further by checking out our Comprehensive List of Adjectives Starting with "O" linked below on this page.

Adjective	Meaning	Synonyms
Overjoyed	Extremely happy or delighted	Elated, euphoric, thrilled
Optimistic	Hopeful and confident about the future	Positive, hopeful, sanguine
Overwhelmed	Feeling overcome with emotions	Overcome, dazed, shaken
Offended	Feeling insulted or hurt	Upset, insulted, affronted
Outraged	Extremely angry or shocked	Infuriated, incensed, offended
Ominous	Suggesting something bad will happen	Foreboding, threatening, sinister
Overconfident	Excessively sure of oneself	Arrogant, presumptuous, cocky
Obsessive	Excessively focused on something	Fixated, compulsive, fanatical
Overbearing	Domineering and controlling	Bossy, domineering, authoritarian
Openhearted	Kind, generous, and emotionally honest	Generous, kind, sincere
Outspoken	Expressing opinions freely	Frank, candid, vocal
Oblivious	Not aware or concerned about something	Unaware, inattentive, heedless
Overanxious	Excessively worried or nervous	Apprehensive, uneasy, fretful
Oppressed	Burdened emotionally or mentally	Weighed down, overwhelmed, distressed
Open	Emotionally accessible or honest	Receptive, transparent, approachable
Outlandish	Emotionally shocking or bizarre	Eccentric, strange, unconventional
Optimized	Feeling improved or enhanced	Refined, bettered, honed
Overawed	Impressed to the point of feeling overwhelmed	Amazed, humbled, daunted
Organized	Emotionally structured and composed	Systematic, orderly, methodical
Outdated	Emotionally stuck in the past	Old-fashioned, antiquated, obsolete

Discover Over 850+ Adjectives Starting with "O" Complete with Meanings and Synonyms

Each adjective in this guide is paired with detailed definitions and carefully chosen synonyms, giving you a thorough understanding of its meaning and versatile usage. Whether you're a writer seeking the perfect word to enrich your descriptions, a student aiming to broaden your vocabulary, or a language enthusiast striving to enhance your expressive skills, this resource is tailored to help you excel. Dive into this guide to improve your linguistic abilities, spark your creativity, and achieve greater clarity and precision in your communication.

Adjective	Meaning	Synonyms
Oafish	Clumsy or awkward in behavior	Clumsy, ungainly, loutish
Oaken	Made of or resembling oak wood	Wooden, sturdy, oak-like
Obdurant	Stubbornly refusing to change	Stubborn, unyielding
Obdurate	Unmoved by persuasion	Stubborn, inflexible, adamant
Obedible	Willing to obey	Obedient, compliant
Obedient	Willing to comply with orders	Compliant, submissive
Obediential	Relating to obedience	Compliant, dutiful
Obeisant	Showing respect or deference	Respectful, deferential
Obese	Extremely overweight	Overweight, fat, corpulent
Obfuscatory	Intended to confuse or obscure	Misleading, confusing, perplexing
Obituary	Relating to death notices	Death-related, memorial
Object-based	Focused on objects or tangible items	Concrete, material, item-focused
Objectionable	Causing offense or disapproval	Offensive, unacceptable, inappropriate
Objectional	Subject to objection or disapproval	Disputable, controversial
Objective	Not influenced by personal feelings; based on facts	Impartial, unbiased, factual
Objectless	Lacking a specific goal or purpose	Aimless, purposeless
Objectual	Relating to objects	Concrete, material
Oblate	Flattened at the poles	Flattened, elliptical
Obligate	Bound to a particular purpose or function	Compulsory, necessary
Obligated	Required by duty or promise	Bound, compelled
Obligational	Relating to obligations	Binding, compulsory
Obligatory	Required by law or rule	Mandatory, required
Obliged	Grateful or indebted	Thankful, appreciative
Obliging	Willing to help	Helpful, accommodating
Oblike	Shaped obliquely or slanted	Angled, slanted
Oblimin	Relating to statistical rotation	Rotational, statistical
Oblique	Not direct or straightforward	Indirect, slanted
Oblite	Obliterated or worn out	Destroyed, faded
Obliterable	Capable of being erased or destroyed	Removable, erasable
Obliterated	Destroyed or erased	Erased, wiped out
Obliterative	Serving to erase or destroy	Destructive, eradicative
Oblivious	Unaware or forgetful	Unmindful, unobservant
Oblong	Having an elongated shape	Elongated, rectangular
Obnoxious	Highly offensive or unpleasant	Annoying, offensive
Obnubilated	Clouded or obscured	Dimmed, veiled
Obscene	Offensive to morality or decency	Indecent, offensive
Obscurant	Serving to obscure or hide	Confusing, obscuring
Obscure	Not easily understood or clearly expressed	Vague, unclear
Obsequious	Excessively eager to please	Servile, fawning
Observable	Able to be seen or noticed	Noticeable, visible
Observant	Quick to notice things	Perceptive, attentive
Observational	Relating to observing	Analytical, watchful
Observed	Noticed or seen	Noted, recorded
Observing	Watching or noticing closely	Watchful, vigilant
Obsessed	Having an intense preoccupation	Fixated, preoccupied
Obsessional	Relating to obsession	Compulsive, fixated
Obsessive	Excessively preoccupied with something	Compulsive, fixated
Obsidian	Relating to volcanic glass	Glassy, dark
Obsignatory	Relating to a seal or approval	Confirmatory, approving
Obsolescent	Becoming outdated or obsolete	Outdated, archaic
Obsolete	No longer in use or outdated	Outdated, old-fashioned
Obsoleter	More outdated than another	Antiquated, superannuated
Obstacle-ridden	Full of obstacles	Challenging, difficult
Obstacular	Relating to or creating obstacles	Obstructive, hindering
Obstetric	Relating to childbirth	Birth-related, maternal
Obstinant	Stubbornly refusing to change one’s opinion	Stubborn, unyielding, inflexible
Obstinate	Stubbornly refusing to change	Stubborn, unyielding
Obstreperous	Noisily defiant or unruly	Boisterous, unmanageable
Obstructed	Blocked or closed off	Blocked, hindered
Obstructive	Causing obstruction	Blocking, hindering
Obstruent	Blocking or constricting	Restrictive, obstructive
Obtainable	Capable of being acquired	Accessible, achievable
Obtrusive	Noticeably intrusive or prominent	Intrusive, conspicuous
Obtundent	Blunting or dulling the edge	Dulling, numbing
Obtuse	Lacking sharpness or intellect	Dull, slow-witted
Obtuse-angled	Having an angle greater than 90 degrees	Wide-angled
Obverse	The front or main side	Front, main side
Obviable	Capable of being avoided or removed	Avoidable, preventable
Obviating	Removing or preventing a need	Preventing, avoiding
Obvious	Easily perceived or understood	Clear, evident
Occasional	Happening now and then	Sporadic, infrequent
Occidental	Relating to the Western world	Western, European
Occipital	Relating to the back of the head	Posterior, cranial
Occluded	Closed off or blocked	Blocked, obstructed
Occlusal	Relating to the biting surface of teeth	Dental, biting
Occluse	Closed or shut off	Sealed, closed, blocked
Occlusional	Relating to occlusion or closure	Closing, sealing
Occlusive	Serving to block or seal	Sealing, obstructive
Occulent	Hidden or concealed	Secret, hidden
Occulomotor	Relating to eye movement	Eye-moving, ocular
Occult	Relating to mysterious or supernatural practices	Mystic, esoteric
Occultic	Associated with occult practices	Mystical, esoteric
Occultistic	Involving occult knowledge or practices	Arcane, mystical
Occultive	Serving to hide or conceal	Concealing, hidden
Occultural	Relating to occult culture or practices	Esoteric, arcane
Occupational	Relating to a job or occupation	Work-related, professional
Occupiable	Capable of being occupied	Usable, inhabitable
Occupied	Engaged or in use	Engaged, taken
Occurrent	Happening or occurring	Present, ongoing
Ocean-going	Designed for travel on the ocean	Seafaring, marine
Oceanic	Relating to the ocean	Marine, sea-related
Oceanward	Directed toward the ocean	Seaward, ocean-bound
Ocellar	Relating to small eyes or eye-like markings	Eye-like, spotted
Ocellated	Having eye-like spots	Spotted, marked
Ocher	Relating to an earthy yellow or red color	Earthy, yellowish
Ochre	Having an ochre or yellow-brown color	Yellowish, earthy
Ochreous	Containing or resembling ochre	Yellowish, brownish
Ocreate	Having sheath-like structures	Sheathed, encased
Octabasic	Containing eight basic groups	Eight-based, octa-basic
Octacore	Having eight cores	Multicore, eight-core
Octacosanoic	Relating to a type of fatty acid	Fatty, chemical
Octacyclic	Containing eight rings in its structure	Multiring, complex
Octagonal	Having eight sides and angles	Eight-sided, polygonal
Octahedral	Having eight faces	Eight-faced, polyhedral
Octal	Relating to the number eight or base-8 numeral system	Base-8, numeral-based
Octameric	Having eight parts	Eight-part, segmented
Octangular	Having eight angles	Eight-angled, polygonal
Octanoic	Relating to an eight-carbon fatty acid	Fatty, chemical
Octogynous	Having eight pistils in botany	Eight-pistil, botanical
Octoic	Containing or relating to eight elements	Eight-based, compound
Octoid	Resembling the shape or structure of eight	Eight-like, structured
Octolateral	Having eight sides	Eight-sided, polygonal
Octolocular	Having eight cells or compartments	Eight-celled, segmented
Octonary	Relating to the number eight	Eight-based, octagonal
Octonionic	Relating to a mathematical system involving eight units	Eight-unit, mathematical
Octonocular	Having eight eyes	Eight-eyed, multiple-eyed
Octopaminergic	Relating to octopamine, a neurotransmitter	Neurochemical, biological
Octopartite	Divided into eight parts	Eight-part, segmented
Octopean	Resembling or relating to an eight-fold structure	Eightfold, complex
Octopetalous	Having eight petals	Eight-petal, botanical
Octopian	Relating to eight as a structural concept	Eight-structured, complex
Octopic	Involving or having eight perspectives	Eight-viewed, multiple
Octopine	Related to a type of compound found in octopuses	Marine, compound
Octoploid	Having eight sets of chromosomes	Eight-chromosome, polyploid
Octopodous	Having eight feet or legs	Eight-legged, multi-legged
Octopoidal	Resembling an octopus	Eight-limbed, cephalopodic
Octosyllabic	Having eight syllables	Eight-syllable, rhythmic
Octuple	Consisting of eight parts	Eightfold, multiple
Ocular	Relating to the eye or vision	Visual, optic
Odd	Different from what is usual or expected	Unusual, strange
Oddish	Slightly odd or peculiar	Quirky, slightly strange
Odds-on	Highly likely or favored to win	Likely, probable, favored
Odd-toed	Having an odd number of toes on each foot	Ungulate, hoofed
Odic	Relating to an invisible force or energy	Energetic, forceful
Odiferous	Having a strong or distinctive odor	Fragrant, aromatic
Odinic	Relating to the Norse god Odin	Mythological, Norse
Odious	Extremely unpleasant; repulsive	Hateful, repugnant, offensive
Odobenine	Relating to walruses	Walrus-like, marine
Odometric	Relating to measurement of distance	Measuring, distance-based
Odometrical	Pertaining to an odometer or distance measurement	Distance-measuring, odometric
Odontoid	Shaped like a tooth	Tooth-like, dental
Odorant	Having or imparting a smell	Fragrant, scented
Odoriferous	Emitting a smell, especially a pleasant one	Fragrant, aromatic
Odorless	Without a smell	Scentless, unscented
Odorous	Having a smell, especially a strong one	Fragrant, aromatic
Odourful	Full of smell or fragrance	Fragrant, aromatic
Odourless	Without odor or smell	Scentless, unscented
Oecumenic	Relating to worldwide or general religious unity	Universal, inclusive
Oecumenical	Promoting unity among Christian churches	Universal, inclusive
Oedematous	Characterized by swelling	Swollen, puffed
Oedipal	Relating to the Oedipus complex	Psychological, Freudian
Oenological	Relating to the study of wine	Wine-related, viticultural
Oenophilic	Showing a love for wine	Wine-loving, connoisseur
Oestral	Relating to the estrus cycle in animals	Fertile, estrous
Oestrogenic	Relating to estrogen or its effects	Hormonal, estrogen-related
Oestrous	Relating to the reproductive cycle in animals	Fertile, estral
Off	Not operating or turned off	Inactive, switched off
Off-air	Not being broadcast	Not on air, inactive
Off-base	Not accurate or mistaken	Wrong, incorrect
Off-beam	Unusual or mistaken	Incorrect, off-track
Offbeat	Unconventional or unusual	Unorthodox, quirky
Off-book	Done without a script or written notes	Unscripted, improvised
Off-broadway	Outside the main Broadway theater district	Independent, alternative
Off-campus	Located outside the university campus	Non-campus, external
Off-center	Not precisely in the center	Asymmetrical, unaligned
Off-colour	Not feeling well; improper or indecent	Unwell, improper
Off-duty	Not on active duty or work	Not working, off-shift
Offenceless	Without offense or harm	Harmless, inoffensive
Offended	Feeling insulted or hurt	Insulted, hurt
Offending	Causing offense or annoyance	Annoying, displeasing
Offensive	Causing displeasure or resentment	Insulting, repugnant
Off-field	Occurring outside the field or play area	External, non-game-related
Off-guard	Unprepared or taken by surprise	Unprepared, surprised
Offhand	Without preparation or forethought	Casual, spontaneous
Officious	Assertive of authority in an annoyingly domineering way	Meddlesome, intrusive
Offish	Aloof or unfriendly	Reserved, distant
Off-key	Not in harmony or out of tune	Out of tune, discordant
Off-kilter	Unbalanced or not functioning normally	Unstable, skewed
Off-limits	Not accessible or permitted	Restricted, prohibited
Offline	Not connected to a network or internet	Disconnected, off-grid
Off-peak	Not during the busiest or most popular time	Low-traffic, non-peak
Off-piste	Not on the main ski slopes	Unmarked, non-standard
Off-putting	Unpleasant or repellent	Distasteful, unappealing
Off-road	Designed for rough terrain, not paved roads	All-terrain, rugged
Off-sale	Relating to the sale of alcohol to take away	Takeaway, to-go
Offscreen	Not shown within the screen or frame	Out of view, behind the scenes
Offshore	Located or based outside the country	Abroad, foreign-based
Offside	In an illegal position in sports	Illegal, foul
Offsite	Located away from a particular site or place	Remote, external
Offstage	Not in the view of the audience	Behind the scenes, backstage
Off-street	Not on the main road or street	Private, side-street
Off-target	Not aimed accurately or missing the intended target	Inaccurate, misaligned
Off-the-ball	Not directly involved in the play or action	Peripheral, secondary
Off-the-cuff	Spoken or done without preparation	Unplanned, spontaneous
Off-the-peg	Ready-made and not tailored	Ready-to-wear, standard
Off-the-rack	Mass-produced and not custom-made	Ready-made, store-bought
Off-the-record	Not intended for public release or official reporting	Confidential, informal
Off-the-shelf	Standard or readily available	Pre-made, generic
Off-the-shoulder	Clothing style that exposes the shoulders	Shoulder-baring, open-shouldered
Off-the-wall	Unconventional or unusual	Quirky, eccentric
Off-track	Not following the planned course or path	Lost, diverted
Off-white	A pale or slightly yellowish white color	Ivory, cream
Oft-repeated	Repeated often	Frequent, reiterated
Ogival	Having the shape of an ogive or pointed arch	Pointed, arched
Ogreish	Resembling an ogre; monstrous or frightening	Monstrous, frightening
Ohmic	Relating to electrical resistance measured in ohms	Resistive, electrical
Oily	Containing or resembling oil	Greasy, slick
Okay	Satisfactory or acceptable	Fine, alright
Old	Having existed for a long time	Ancient, aged
Olde	An archaic or poetic form of "old"	Antique, ancient
Olden	Belonging to the past; ancient	Bygone, ancient
Older	Having more age than something else	Elder, senior
Oldest	Having the greatest age	Most ancient, senior-most
Old-fashioned	No longer in style or current	Outdated, vintage
Old-growth	Relating to mature and ancient forests	Ancient, primeval
Old-hat	No longer fresh or exciting	Outdated, stale
Oldish	Somewhat old or aged	Middle-aged, aging
Old-line	Traditional or long-established	Conservative, traditional
Old-maidish	Prudish or overly conservative	Prudish, spinsterish
Old-school	Characteristic of an earlier style	Traditional, classic
Old-time	Relating to an earlier time	Historic, traditional
Old-world	Having qualities associated with the past	Classic, antique
Ole	A poetic or dialectal form of "old"	Old, vintage
Oleaginous	Containing or resembling oil	Greasy, slick
Oleanolic	Relating to a type of natural compound found in plants	Plant-based, triterpenoid
Olefinic	Relating to or containing olefins (hydrocarbons)	Hydrocarbon-based, organic
Oleic	Relating to or containing oleic acid	Fatty, unsaturated
Olent	Having a strong odor or smell	Odorous, aromatic
Oleochemical	Relating to chemicals derived from plant or animal fats	Bio-based, fatty acid-based
Oleographic	Relating to lithographic printing in oils	Artistic, oil-based
Oleophilic	Having a strong affinity for oils	Oil-loving, hydrophobic
Oleophobic	Resistant to or repellent of oils	Oil-repellent, non-stick
Oleoresinous	Containing both oil and resin	Resinous, sticky
Oleose	Oily or greasy in nature	Oily, greasy
Oleraceous	Relating to or resembling vegetables	Vegetable-like, green
Olfactive	Relating to the sense of smell	Olfactory, nasal
Olfactory	Concerning the sense of smell	Scent-related, nasal
Oligaemic	Relating to a deficiency of blood	Anemic, blood-deficient
Oligarchic	Relating to oligarchy; ruled by a few	Authoritarian, exclusive
Oligarchical	Characterized by oligarchy	Power-centralized, ruling-class
Oligomeric	Relating to a molecule composed of a few repeating units	Small-chain, polymer-based
Oligopolistic	Relating to an oligopoly; controlled by a few entities	Market-controlled, monopolistic
Oligosaline	Having low levels of salinity	Low-salt, slightly saline
Oligosemic	Having few meanings	Univocal, limited in meaning
Oligosynaptic	Involving few synapses	Simple, nerve-related
Oligotrichous	Having few hairs	Sparse-haired, scanty
Oligotrophic	Low in nutrients, especially in lakes	Unfertile, low-nutrient
Oliguric	Relating to low urine output	Low-output, deficient
Olivary	Resembling or related to an olive	Olive-shaped, greenish
Olive	Dark yellow-green in color	Greenish, olive-colored
Olivelike	Resembling an olive in shape or color	Olive-shaped, greenish
Olympian	Relating to the Olympic Games or grand scale	Majestic, grand
Olympic	Relating to the Olympic Games	Athletic, competitive
Omani	Relating to Oman or its people	Middle Eastern, Arabian
Omasal	Relating to the omasum in ruminants	Stomach-related, digestive
Ominous	Suggesting something bad is about to happen	Threatening, foreboding
Omissible	Capable of being omitted	Excludable, dispensable
Omissive	Relating to or involving omission	Excluding, skipping
Ommatidial	Relating to the visual units in compound eyes	Ocular, compound-eye
Omnibus	Including many items or aspects	Comprehensive, all-encompassing
Omnipotent	Having unlimited power	All-powerful, almighty
Omnipresent	Present everywhere at the same time	Ubiquitous, all-present
Omniscient	Knowing everything	All-knowing, wise
Omnivorous	Eating both plants and animals	All-eating, versatile
Omohyoidean	Relating to a muscle between the shoulder and hyoid bone	Anatomical, muscular
Omophagic	Eating raw meat	Raw-meat-eating, carnivorous
Omophagous	Consuming raw meat	Raw-meat-eating, carnivorous
Omosternal	Relating to the shoulder and sternum	Anatomical, bone-related
Omotic	Relating to the Omotic language family	Linguistic, Ethiopian
Omphacine	Relating to unripe fruit	Green, unripe
Omphacitic	Relating to a specific type of greenish rock	Mineral, jade-like
Omphalic	Relating to the navel or umbilicus	Navel-related, umbilical
Omphalinoid	Resembling the navel	Umbilical, navel-shaped
On	Activated or in operation	Active, operational
On-air	Currently broadcasting	Broadcasting, live
Onanistic	Relating to self-stimulation	Self-indulgent, solitary
On-camera	Appearing on video or television	Recorded, televised
On-campus	Located within a university or school campus	Campus-based, internal
Once-removed	Relating to a degree of family separation (e.g., cousin once-removed)	Distant, indirect
Oncogenetic	Relating to the formation of tumors or cancer	Cancer-causing, tumorigenic
Oncogenic	Causing or likely to cause cancer	Cancerous, carcinogenic
Oncogenomic	Relating to the study of cancer genes	Genomic, cancer-related
Oncologic	Relating to the study and treatment of tumors	Cancer-related, medical
Oncological	Relating to oncology or cancer treatment	Medical, tumor-related
Oncoming	Approaching or coming nearer	Approaching, forthcoming
One-armed	Having only one arm	Single-armed, partial
One-day	Lasting or occurring within a single day	Single-day, 24-hour
One-eighth	Equal to one part of eight equal parts	Octant, fractional
One-eyed	Having only one eye	Single-eyed, monocular
One-fifth	Equal to one part of five equal parts	Quintile, fractional
One-fourth	Equal to one part of four equal parts	Quarter, fractional
One-gallused	Having only one strap or gallus	Single-strapped
One-half	Equal to one of two equal parts	Half, semi
One-handed	Using or having only one hand	Single-handed, partial
One-legged	Having only one leg	Single-legged, partial
One-ninth	Equal to one part of nine equal parts	Ninth part, fractional
One-note	Monotonous or limited in scope	Repetitive, monotone
One-off	Occurring only once; unique	Single, unique
One-on-one	Involving two people in direct interaction	Individual, face-to-face
One-piece	Made in one single piece	Single-piece, undivided
One-pot	Cooked or prepared in a single pot	Single-pot, simple
One-quarter	Equal to one of four equal parts	Quarter, fractional
Onerous	Involving a great deal of effort or difficulty	Burdensome, heavy
One-seventh	Equal to one of seven equal parts	Seventh part, fractional
One-shot	Occurring only once	Single, unique
Onesided	Biased or focusing on one side only	Partial, one-sided
One-sixth	Equal to one of six equal parts	Sixth part, fractional
One-stop	Providing a complete range of services	Comprehensive, full-service
One-tenth	Equal to one of ten equal parts	Tenth part, fractional
One-third	Equal to one of three equal parts	Third part, fractional
Onetime	Occurring only once; former	Single, former
One-time	Done or occurring only once	Single-use, unique
One-to-one	Directly corresponding one to one	Direct, individual
One-touch	Achieved with a single touch or action	Single-touch, easy
One-track	Limited in focus or narrow-minded	Narrow, focused
One-way	Allowing travel or movement in one direction only	Unidirectional, single-direction
Ongoing	Continuing or currently happening	Continuing, current
On-hand	Available or accessible	Available, ready
Onioned	Containing or flavored with onions	Onion-flavored, spiced
Onionless	Without onions	Plain, without onions
Onionlike	Resembling an onion	Onion-shaped, similar to onion
Oniony	Having a strong onion smell or taste	Onion-flavored, pungent
Oniric	Relating to dreams	Dreamlike, surreal
Onirocritic	Relating to the interpretation of dreams	Dream-interpreting, analytical
Onkus	Unpleasant or difficult	Hard, difficult
Onlest	Unless or except	Except, unless
Onlie	Scottish term for only	Single, sole
Online	Connected to or available on the internet	Connected, digital
On-looking	Watching or observing something	Observant, watchful
Only	Single; no other	Single, sole
On-off	Alternating between on and off states	Switchable, intermittent
Onomastic	Relating to names or naming	Naming-related, nominative
Onomatopoeic	Imitative of a sound	Sound-mimicking, expressive
On-road	Designed for use on paved roads	Pavement-ready, road-suitable
Onrushing	Moving swiftly toward something	Approaching, advancing
On-scene	Present at the location where something is happening	Present, on-site
Onscreen	Appearing or shown on a screen	Displayed, on-display
On-screen	Visible or occurring on a screen	Visible, displayed
Onshore	Located on or near land, especially near the coast	Coastal, land-based
Onside	In a legally acceptable position in sports	Legal, permissible
Onsite	Located at a particular site	On-location, at-place
On-stage	Appearing or happening on a stage	Performing, visible
On-the-job	Relating to activities done while working	Work-related, hands-on
On-the-spot	Happening immediately or in place	Instantaneous, immediate
Ontic	Relating to entities and their existence	Existential, real
Ontogenetic	Relating to the development of an organism	Developmental, biological
Ontologic	Relating to the nature of being	Philosophical, existential
Ontological	Concerning the study of being and existence	Existential, metaphysical
Onward	Moving forward or continuing	Forward, progressing
Onygenaceous	Relating to a family of fungi	Fungal, mycological
Onymous	Having a known name or identity	Identified, named
Onyx	Relating to a type of gemstone	Gem-like, stone-based
Oolitic	Composed of small, spherical grains	Grainy, textured
Oozy	Resembling or covered in ooze	Muddy, slimy
Opacating	Causing something to become opaque	Darkening, clouding
Opacifiable	Capable of being made opaque	Cloudable, darkenable
Opacous	Opaque or lacking transparency	Cloudy, non-transparent
Opacular	Somewhat opaque or cloudy	Foggy, semi-transparent
Opalescent	Showing a play of colors; iridescent	Iridescent, shimmering
Opaline	Resembling opal; milky and iridescent	Pearlescent, lustrous
Opaque	Not allowing light to pass through	Non-transparent, cloudy
Open	Not closed or accessible	Accessible, available
Openable	Capable of being opened	Unlockable, accessible
Open-air	Outdoors or in an unenclosed space	Outdoor, open-space
Open-and-shut	Simple and straightforward	Clear-cut, obvious
Open-armed	Welcoming or receptive	Hospitable, welcoming
Open-book	Transparent or easily understood	Clear, straightforward
Opencast	Relating to surface mining	Surface-level, above-ground
Opencut	Relating to a mining technique where minerals are extracted from the surface	Surface mining, above-ground
Opened	Not closed or unlocked	Accessible, unsealed
Open-ended	Without a fixed limit or end	Unlimited, flexible
Open-eyed	Alert or watchful	Attentive, observant
Open-faced	Having an honest or sincere expression	Sincere, genuine
Open-handed	Generous and giving	Liberal, generous
Open-hearted	Friendly and kind-hearted	Kind, compassionate
Open-hearth	Relating to a type of furnace for smelting	Furnace-based, smelting
Opening	Serving as an introduction or beginning	Introductory, beginning
Open-minded	Willing to consider new ideas	Receptive, flexible
Open-mouthed	Surprised or amazed	Astonished, agape
Open-plan	Having few or no internal walls	Unpartitioned, spacious
Opensightly	Easily visible or unobstructed	Clear, unobstructed
Opensource	Software with publicly accessible source code	Free, community-driven
Opephoroid	Relating to a type of plant part	Botanical, plant-based
Operable	Capable of being used or operated	Functional, usable
Operant	Functioning or having an effect	Active, effective
Operatic	Relating to opera	Dramatic, theatrical
Operating	In action or functioning	Functioning, running
Operational	Ready for use; functional	Functional, active
Operationalist	Based on operational definitions	Practical, functional
Operative	Functioning or having effect	Active, effective
Opercular	Relating to a covering or lid	Covering, protective
Operculate	Having a lid or covering	Covered, protected
Operculated	Having a lid or covering	Covered, protected
Operose	Involving much labor; tedious	Laborious, strenuous
Ophidian	Relating to or resembling snakes	Serpentine, snake-like
Ophiolitic	Relating to a complex of rocks from the oceanic crust	Rock-based, geological
Opiate	Containing or resembling opium	Narcotic, sedative
Opinionated	Holding stubbornly to one's own opinions	Dogmatic, assertive
Oppilative	Causing obstruction or blockage	Obstructive, blocking
Opportune	Occurring at a favorable moment	Timely, convenient
Opportunistic	Taking advantage of circumstances	Exploitative, self-serving
Opposable	Capable of being placed against something	Moveable, flexible
Opposed	Against or in conflict with something	Contrary, antagonistic
Opposing	Acting against or in opposition	Counteracting, adversarial
Opposite	Completely different; contrary	Contrary, opposing
Oppositional	Resisting or opposing	Contrary, adversarial
Oppositive	Characterized by opposition	Contrary, opposing
Oppressed	Suffering under unfair treatment or control	Persecuted, subjugated
Oppressional	Relating to oppression or domination	Controlling, authoritarian
Oppressive	Weighing heavily on the mind or spirits	Tyrannical, harsh
Opprobrious	Expressing scorn or criticism	Insulting, derogatory
Opsonic	Relating to opsonins, which enhance immune response	Immune-boosting, immunologic
Optative	Expressing a wish or desire	Wishing, hopeful
Ophthalmic	Relating to the eye or vision	Ocular, visual
Optic	Relating to the eye or vision	Ocular, visual
Optical	Relating to sight or vision	Visual, ocular
Optimal	Best or most favorable	Ideal, best
Optimific	Producing the best outcome	Beneficial, favorable
Optimistic	Hopeful and confident about the future	Hopeful, positive
Optimum	The most favorable condition or outcome	Best, ideal
Optional	Available as a choice	Elective, discretionary
Optoelectronic	Relating to electronic devices that interact with light	Photonics, light-based
Optokinetic	Relating to movement and sight	Visual-motor, kinetic
Optomotor	Relating to motor responses to visual stimuli	Visual-motor, reactive
Optothermal	Relating to the interaction between heat and light	Heat-based, photothermal
Optotypic	Relating to eye test symbols	Ocular, visual-test
Optronic	Combining optical and electronic technology	Photonics, light-based
Opulent	Luxurious or lavish	Wealthy, rich
Opuntiaceous	Relating to the cactus family Opuntia	Cactus-like, succulent
Oracular	Relating to prophecy or predictions	Prophetic, mysterious
Oral	Relating to the mouth or speech	Spoken, verbal
Orange	Having a bright reddish-yellow color	Reddish-yellow, citrus-colored
Orangey	Somewhat orange in color	Orange-tinted, citrus-like
Orangish	Resembling the color orange	Orange-tinted, citrus-like
Orangy	Having a hue of orange	Orange-colored, citrus-like
Oratorial	Relating to public speaking	Rhetorical, speech-like
Oratorian	Relating to the Oratorian order or society	Religious, ecclesiastical
Oratorical	Relating to the art of public speaking	Eloquent, rhetorical
Orbicular	Shaped like a disc or sphere	Round, circular
Orbiculate	Having a circular or nearly circular shape	Rounded, circular
Orbitary	Relating to an orbit or path	Orbital, revolving
Orbitual	Relating to the eye socket or orbit	Ocular, orbital
Orbless	Without or lacking an orb or sphere	Sphereless, circular-free
Orblike	Resembling an orb or sphere	Spherical, round
Orchestral	Relating to or suitable for an orchestra	Symphonic, musical
Orchestrated	Arranged or directed skillfully	Coordinated, arranged
Orcish	Relating to or resembling orcs	Beastly, monstrous
Ordained	Officially appointed or invested	Appointed, consecrated
Orderable	Capable of being ordered or requested	Requestable, obtainable
Ordered	Organized or arranged in a specific way	Organized, systematic
Orderly	Neatly and methodically arranged	Organized, tidy
Ordinal	Relating to order or sequence	Sequential, numerical
Ordinary	Common or usual; not special	Commonplace, typical
Ordinate	Relating to coordinates in geometry	Geometric, positional
Ordurous	Relating to filth or waste	Foul, filthy
Orectic	Relating to desire or appetite	Appetitive, craving
Oregonian	Relating to Oregon or its people	Regional, American
Organic	Relating to living matter or derived naturally	Natural, biological
Organismal	Relating to organisms or living beings	Biological, life-based
Organismic	Relating to organisms	Biological, organism-related
Orgasmic	Relating to or causing intense pleasure	Intense, ecstatic
Orgastic	Relating to the climax of intense pleasure	Ecstatic, euphoric
Orgulous	Archaic term for proud or haughty	Proud, haughty
Orient	Relating to the eastern world	Eastern, Asian
Oriental	Relating to the East or Asia	Eastern, Asian
Orientated	Adjusted or aligned to something	Aligned, directed
Orientating	Adjusting or aligning oneself	Aligning, positioning
Orientational	Relating to position or alignment	Positional, directional
Oriented	Focused or directed toward something	Aligned, directed
Orienting	Positioning or aligning	Adjusting, aligning
Origenian	Relating to the teachings of Origen	Theological, doctrinal
Origenist	Following the teachings of Origen	Theological, doctrinal
Origenistic	Conforming to the ideas of Origen	Doctrinal, theological
Originable	Capable of being originated	Creatable, initiatable
Original	Existing from the beginning; authentic	Authentic, first
Originary	Existing from the beginning	Original, initial
Originative	Relating to the power of creating or producing	Creative, inventive
Originless	Without an identifiable beginning	Untraceable, beginningless
Orinasal	Relating to the mouth and nose	Oral-nasal, facial
Orinocan	Relating to the Orinoco River or region	Regional, geographical
Orkish	Resembling or relating to orcs	Monstrous, beastly
Ornamental	Serving as decoration	Decorative, embellishing
Ornate	Elaborately decorated or intricate	Detailed, fancy
Ornery	Bad-tempered or combative	Grumpy, irritable
Ornithogenic	Produced by birds	Bird-related, avian
Ornithological	Relating to the study of birds	Bird-study, avian
Ornithophilous	Pollinated by birds	Bird-pollinated, avian
Orogastric	Relating to the mouth and stomach	Gastric, digestive
Orogenic	Relating to the formation of mountains	Mountain-forming, geological
Orogenital	Relating to the mouth and genitals	Anatomical, bodily
Orographic	Relating to the study of mountains	Mountain-related, geographical
Orographical	Concerning the physical geography of mountains	Geographical, mountain-based
Orolabial	Relating to the mouth and lips	Oral, labial
Orolingual	Relating to the mouth and tongue	Oral, lingual
Orological	Relating to the study of mountains	Geological, mountain-related
Oromucosal	Relating to the mouth and mucous membranes	Mucosal, oral
Oronasal	Relating to the mouth and nose	Oral-nasal, respiratory
Oroqen	Relating to the Oroqen ethnic group of China	Ethnic, cultural
Orosensory	Relating to taste or sensory perceptions in the mouth	Taste-related, sensory
Orosirian	Relating to the Orosirian period in Earth's history	Geological, ancient
Orotund	Full, round, and imposing in sound	Resonant, sonorous
Orphaned	Left without parents or guardians	Abandoned, parentless
Orphic	Mystical or relating to Orpheus	Enigmatic, mystical
Orthodontic	Relating to the correction of teeth alignment	Dental, corrective
Orthodox	Conforming to established beliefs or practices	Conventional, traditional
Orthoepic	Relating to correct pronunciation	Phonetic, pronunciation-related
Orthogenetic	Relating to straight or directed development	Progressive, developmental
Orthogenic	Relating to guided development	Corrective, progressive
Orthognathic	Relating to jaw alignment	Dental, alignment-related
Orthogonal	At right angles; independent	Perpendicular, uncorrelated
Orthograde	Walking upright on two legs	Upright, bipedal
Orthologous	Relating to genes in different species with similar function	Genetic, evolutionary
Orthometric	Relating to accurate measurement	Measured, precise
Orthopedic	Relating to the correction of bones and muscles	Skeletal, corrective
Orthoptic	Relating to vision correction	Ocular, visual-corrective
Orthorhombic	Relating to a crystal system with three unequal axes	Crystalline, geometrical
Orthostatic	Relating to standing upright	Upright, vertical
Orthotopic	Relating to the normal position of an organ	Correct-position, anatomical
Orthotropic	Relating to growth in response to stimulus direction	Directional, growth-responsive
Os	Relating to bone or bone structure	Bony, skeletal
Oscillating	Moving back and forth at regular intervals	Swinging, vibrating
Oscillatory	Characterized by oscillation	Vibratory, periodic
Oscine	Relating to songbirds	Avian, songbird-related
Oscitant	Yawning or drowsy	Drowsy, lethargic
Osculating	Relating to or involving kissing	Kissing, touching
Osculatory	Of or relating to kissing	Kissing, affectionate
Osmobiotic	Relating to living organisms in high osmotic pressure	Osmotic, pressure-related
Osmolar	Relating to the concentration of solutions	Concentrative, solution-based
Osmometric	Relating to osmotic pressure measurement	Measurement-based, solution-related
Osmotic	Relating to osmosis	Diffusive, membrane-related
Osseous	Relating to or resembling bone	Bony, skeletal
Ossicular	Relating to the small bones in the ear	Auditory, small-boned
Ossiculate	Having small bone structures	Bony, skeletal
Ossiferous	Containing or producing bone	Bony, bone-forming
Ossified	Turned into bone; hardened	Calcified, hardened
Ossom	Relating to bone	Bony, skeletal
Os-specific	Specific to bone	Bone-specific, skeletal
Osteal	Relating to bone	Bony, skeletal
Ostensible	Appearing to be true but possibly not so	Apparent, seeming
Ostensive	Directly demonstrating or showing	Demonstrative, explanatory
Ostentatious	Characterized by vulgar or pretentious display	Showy, pretentious
Osteoarthritic	Relating to osteoarthritis	Arthritic, joint-related
Osteogenetic	Relating to the formation of bone	Bone-forming, skeletal
Osteogenic	Producing or forming bone tissue	Bony, bone-forming
Osteoid	Relating to bone formation	Bone-like, skeletal
Osteopathic	Relating to osteopathy	Medical, musculoskeletal
Osteoporotic	Relating to osteoporosis	Brittle, bone-thinning
Ostial	Relating to an opening or orifice	Aperture-related, opening
Ostrich-like	Resembling an ostrich	Avian, bird-like
Other	Different or distinct from the one already mentioned	Alternate, different
Otherwise	In a different situation or respect	Alternatively, in other ways
Other-worldly	Relating to a mystical or imagined world	Ethereal, supernatural
Otic	Relating to the ear	Auricular, auditory
Otoscopic	Relating to an instrument for examining the ear	Ear-examining, auditory
Ototoxic	Harmful to the organs of hearing	Ear-damaging, toxic
Otter	Relating to or resembling an otter	Animal-like, mustelid
Otterless	Without otters	Otter-free, devoid of otters
Otterlike	Resembling or characteristic of an otter	Otterish, mustelid-like
Out	Not at home or away	Away, absent
Out of work	Unemployed or without a job	Unemployed, jobless
Out-and-out	Absolute or complete	Thorough, utter
Outback	Remote and rural, especially in Australia	Wilderness, rural
Outboard	Situated on the outside, especially of a boat	External, peripheral
Outbound	Going away or leaving	Departing, outgoing
Outbred	Produced by breeding from unrelated individuals	Crossbred, genetically diverse
Outclassed	Surpassed or defeated by a superior	Outdone, bested
Outcoming	Approaching or coming out	Emerging, upcoming
Outcut	Cut beyond or exceeding	Exceeding, surpassing
Outdacious	Archaic term meaning bold or audacious	Bold, daring
Outdate	To be older or outdated	Old-fashioned, obsolete
Outdated	No longer current or fashionable	Old-fashioned, obsolete
Outdoor	Located or used outside	Open-air, outside
Outdoorsy	Fond of or suited to the outdoors	Nature-loving, adventurous
Outer	Located on or towards the outside	External, outside
Outermost	Furthest out or at the farthest distance	Farthest, exterior
Outfitted	Equipped or provided with	Equipped, supplied
Outflowing	Flowing outwards	Outgoing, issuing
Outflung	Thrown or spread out widely	Spread, extended
Outgoing	Friendly and socially confident	Extroverted, sociable
Outgunned	Outmatched or overpowered, especially in arms	Outclassed, overpowered
Outjutting	Projecting outward	Protruding, jutting
Outland	Remote or foreign land	Remote, foreign
Outlandish	Strange or unfamiliar	Bizarre, eccentric
Outlaw	Declared as illegal	Forbidden, illegal
Outlawed	Banned or made illegal	Banned, prohibited
Outlined	Described or summarized	Summarized, described
Outlying	Situated far from a center or remote	Remote, peripheral
Outmoded	No longer in style	Obsolete, outdated
Outmost	Farthest outward	Outermost, farthest
Out-of-body	Relating to experiences outside one's physical self	Transcendental, supernatural
Out-of-character	Not typical of someone's usual behavior	Unusual, atypical
Out-of-context	Removed from the original setting or circumstances	Isolated, misinterpreted
Out-of-court	Resolved without going to trial	Settled, resolved
Out-of-date	No longer current or valid	Obsolete, expired
Out-of-order	Not working or functioning	Broken, malfunctioning
Out-of-pocket	Paid directly by the individual	Self-paid, personal expense
Out-of-print	No longer published or available for sale	Unpublished, unavailable
Out-of-service	Not currently available or in use	Unavailable, inactive
Out-of-state	From or located in another state	External, non-local
Out-of-town	Located outside one's usual town or city	Non-local, external
Out-of-work	Without a job	Unemployed, jobless
Outraged	Extremely angry or shocked	Enraged, infuriated
Outrageous	Shocking or unacceptable	Scandalous, shocking
Outright	Complete and total	Absolute, total
Outshore	Located away from the shore	Offshore, distant
Outside	Located on or towards the outer part	External, outer
Outsize	Larger than usual	Oversized, large
Outsized	Very large or oversized	Oversized, large
Outspoken	Expressing opinions openly	Frank, candid
Outspread	Spread out widely	Extended, expanded
Outstanding	Exceptionally good or impressive	Remarkable, excellent
Outward	Directed towards the outside	External, outward-facing
Ouvrierist	Relating to or supporting working-class interests	Proletarian, labor-focused
Oval	Having an egg-like shape	Elliptical, oblong
Ovaloid	Resembling an oval	Oval-like, elliptical
Ovarian	Relating to the ovaries	Reproductive, female
Ovate	Egg-shaped	Elliptical, oval
Ovation	Relating to enthusiastic applause	Applauded, celebrated
Ovenproof	Safe to use in an oven	Heat-resistant, oven-safe
Oven-proof	Safe for oven use	Heat-resistant, durable
Over	Finished or no longer happening	Ended, done
Overabundant	Excessively abundant	Excessive, plentiful
Overachiever	Someone who achieves more than expected	High-achiever, go-getter
Overachieving	Exceeding set goals or expectations	Ambitious, successful
Overactive	Excessively active or energetic	Hyperactive, restless
Overage	Older than a specified limit	Too old, aged
Overaged	Having passed a specified age limit	Outdated, aged
Overaggressive	Excessively aggressive or forceful	Pushy, hostile
Overalert	Excessively vigilant or cautious	Hyper-vigilant, overly cautious
Overalled	Wearing overalls	Covered, dressed
Overanxious	Excessively anxious or worried	Nervous, apprehensive
Overapt	Excessively inclined or prone	Too eager, overly inclined
Overarm	Relating to a movement performed with the arm above the shoulder	Overhead, above-shoulder
Overattentive	Excessively attentive	Overly alert, hyper-focused
Overawed	Impressed or intimidated by someone or something	Astonished, intimidated
Overbanked	Having too much of a bank or reserve	Excessive, well-supplied
Overbearing	Unpleasantly domineering or arrogant	Domineering, oppressive
Overblown	Excessively inflated or exaggerated	Exaggerated, excessive
Overbold	Excessively bold or daring	Audacious, reckless
Overbooked	Having more reservations than available spots	Fully booked, crowded
Overburdened	Excessively burdened or loaded	Overloaded, overwhelmed
Overbusy	Extremely busy	Occupied, too busy
Overcareful	Excessively cautious	Overly cautious, meticulous
Overcast	Covered with clouds	Cloudy, gray
Overcautious	Too cautious or wary	Timid, apprehensive
Overcharged	Charged too much money	Expensive, overpriced
Overcivilized	Excessively refined or lacking authenticity	Too polished, overly refined
Overclad	Excessively dressed or covered	Overdressed, covered
Overclaimed	Claimed more than is justifiable	Exaggerated, overstated
Overclear	Excessively clear or obvious	Too obvious, evident
Overclose	Excessively close or near	Too close, intimate
Overclothed	Dressed in too many clothes	Overdressed, bundled up
Overcluttered	Filled with too many items, creating disorder	Messy, overcrowded
Overcoached	Trained or guided excessively	Overtrained, micromanaged
Overcoated	Wearing an additional coat or layer	Layered, bundled
Overcoatless	Without an overcoat	Underdressed, unlayered
Overcoming	Succeeding in dealing with a challenge	Conquering, surmounting
Overcommitted	Having committed to too many obligations	Overextended, overwhelmed
Overcomplicated	Made excessively complex	Confusing, convoluted
Overconcerned	Excessively worried	Overly worried, anxious
Overconfident	Excessively self-assured	Arrogant, cocky
Overconscientious	Extremely attentive to detail	Meticulous, scrupulous
Overconscious	Excessively aware	Self-conscious, overly aware
Overconsiderate	Too concerned with others' needs	Overly thoughtful, overly caring
Overcounted	Counted more than once or excessively	Miscounted, double-counted
Overcritical	Excessively fault-finding	Judgmental, harsh
Overcurious	Excessively inquisitive	Nosy, prying
Overdamped	Having excessive damping in a system	Highly restricted, restrained
Overdelicate	Excessively fragile or sensitive	Fragile, sensitive
Overdependent	Excessively reliant on others	Reliant, needy
Overdetermined	Determined by multiple causes	Predetermined, multiply-caused
Overdeveloped	Developed excessively	Advanced, overgrown
Overdocumented	Supported with excessive documentation	Overly recorded, highly detailed
Overdominant	Excessively controlling or influential	Domineering, overbearing
Overdone	Done to excess; overcooked	Exaggerated, overcooked
Overdoped	Given too much of a substance, often a drug	Over-medicated, overtreated
Overdosed	Given an excessive amount of a substance	Over-medicated, overconsumed
Overdramatic	Excessively emotional or theatrical	Melodramatic, exaggerated
Overdressed	Wearing clothes that are too formal or elaborate	Too dressed up, overly formal
Overdue	Not done or paid on time	Late, delayed
Overeager	Excessively enthusiastic	Impatient, excitable
Overeducated	Having more education than is useful	Over-schooled, overqualified
Over-educated	Possessing excessive or irrelevant education	Overqualified, too educated
Over-elaborate	Excessively detailed or complicated	Intricate, overly complex
Overemotional	Excessively emotional or sensitive	Sentimental, touchy
Overemphatic	Excessively emphatic or forceful	Strongly stressed, overstated
Overenthusiastic	Showing excessive enthusiasm	Excitable, too eager
Overexcitable	Easily excited to an excessive degree	Hyperactive, reactive
Overexcited	Excessively excited or enthusiastic	Thrilled, overly eager
Overexerted	Used too much physical or mental energy	Exhausted, fatigued
Overexerting	Using excessive effort	Straining, exhausting
Overexposed	Exposed too much, especially to media or light	Excessively revealed, overpublicized
Overextended	Committed beyond one's capacity	Overstretched, overloaded
Overfamiliar	Excessively familiar or informal	Too friendly, intrusive
Overfatigued	Excessively tired or worn out	Exhausted, drained
Overfed	Given too much food	Stuffed, over-nourished
Overflowing	Filled beyond capacity	Full, spilling over
Overfocused	Having excessive concentration on one thing	Obsessed, too focused
Overfond	Excessively fond or affectionate	Attached, overly affectionate
Over-fond	Too fond or affectionate	Too attached, clingy
Overforceful	Excessively strong or aggressive	Pushy, intense
Overforested	Covered with too many trees	Overgrown, dense
Overforward	Excessively bold or presumptuous	Pushy, intrusive
Overfragrant	Having an excessively strong fragrance	Pungent, strong-smelling
Overfraught	Overfilled or laden with emotional tension	Stressful, tense
Overfree	Excessively free or unrestrained	Uncontrolled, unrestrained
Overfreighted	Excessively loaded or burdened	Overloaded, heavily laden
Overfrequent	Happening too often	Too common, frequent
Overfriendly	Excessively friendly or familiar	Overly social, intrusive
Overfriezed	Having too many ornamental friezes	Overdecorated, ornate
Overfruitful	Excessively productive or fruitful	Abundant, prolific
Overful	Excessively full or overflowing	Overflowing, overfilled
Overfulfilled	Exceeded in fulfillment or achievement	Overachieved, surpassed
Overfull	Containing too much; excessively full	Stuffed, packed
Overfurnished	Decorated or equipped with too much furniture	Cluttered, crowded
Overfussy	Excessively concerned with detail	Meticulous, picky
Overgenerous	Excessively giving or kind	Lavish, magnanimous
Overgreedy	Excessively greedy or selfish	Avaricious, grasping
Overgrown	Grown excessively large or thick	Dense, unkempt
Overhand	Performed with the hand above shoulder level	Overarm, above-shoulder
Overhanded	Using or performed with the hand raised above	High-handed, abovehand
Overhasty	Excessively quick or rash	Hurried, impetuous
Overhead	Above one's head	Aloft, above
Overheated	Made excessively hot	Hot, warmed
Overhyped	Excessively promoted or praised	Overrated, exaggerated
Overinclusive	Containing too much or too many items	All-encompassing, comprehensive
Overindebted	Owing more debt than one can repay	Heavily indebted, overextended
Overintense	Excessively intense or strong	Extreme, overwhelming
Overinvested	Committed too much, especially financially	Overcommitted, overstretched
Overinvolved	Too deeply engaged or absorbed	Too involved, absorbed
Overionized	Having too many ions or charged particles	Highly charged, ion-rich
Overish	Somewhat over or excessive	Excessive, slightly over
Overjealous	Excessively protective or suspicious	Too watchful, overprotective
Overjittery	Extremely nervous or jittery	Nervous, anxious
Overjoyed	Extremely happy or delighted	Thrilled, elated
Overjoyous	Filled with great joy or happiness	Ecstatic, jubilant
Overjubilant	Excessively joyful or celebratory	Elated, jubilant
Overjust	Excessively fair or just	Fair-minded, righteous
Overkeen	Excessively eager or enthusiastic	Excitable, too eager
Overladen	Excessively loaded or burdened	Overburdened, weighed down
Overland	Traveling across land rather than water or air	Land-based, ground
Overlarge	Excessively large	Huge, oversized
Overlayered	Having too many layers	Layered, piled up
Overloaded	Having too much of a load	Overburdened, crowded
Overlookable	Able to be overlooked or ignored	Missable, ignorable
Overlooked	Ignored or not noticed	Unnoticed, disregarded
Overly	Excessively or too much	Too, excessively
Overlying	Lying on top of or covering something	Overlaying, covering
Overmastering	Having overwhelming power or influence	Dominating, overpowering
Overmighty	Excessively powerful or dominant	Overpowering, supreme
Overmodest	Excessively modest or humble	Shy, too modest
Overmotivated	Excessively driven or ambitious	Overzealous, determined
Overmuch	Too much or excessively	Too, excessively
Overmuscled	Having an excessive amount of muscle	Muscular, bulky
Overneat	Excessively tidy or organized	Too neat, meticulous
Overnew	Excessively new or modern	Too modern, ultra-new
Overnice	Excessively nice or polite	Too polite, overly kind
Overnight	Happening or done in a single night	Instant, immediate
Overnighter	One who stays overnight	Stayer, lodger
Overoptimistic	Excessively optimistic	Idealistic, hopeful
Overpessimistic	Excessively pessimistic	Negative, doubtful
Overplayful	Excessively playful or playful to a fault	Jovial, too playful
Over-polite	Excessively polite	Too courteous, deferential
Overpriced	Priced higher than what is reasonable	Expensive, costly
Overproof	Having a higher than normal alcohol content	High-alcohol, strong
Overproud	Excessively proud or arrogant	Arrogant, conceited
Overqualified	Having qualifications beyond what is necessary	Over-skilled, too experienced
Overraced	Exerted too much through racing	Overworked, tired
Overracked	Stressed or strained excessively	Overstretched, stressed
Overrank	Excessively high or luxuriant growth	Overgrown, lush
Overrash	Excessively rash or reckless	Impulsive, reckless
Over-rated	Rated or valued more than is deserved	Exaggerated, hyped
Overreaching	Aiming or trying to do more than possible	Ambitious, overextending
Overreactive	Reacting excessively to stimuli	Hyperreactive, sensitive
Overready	Too eager or prepared	Overeager, impatient
Overrefined	Excessively polished or refined	Too polished, overly meticulous
Overriding	More important than anything else	Primary, dominant
Overripe	Past the point of ideal ripeness	Too ripe, spoiled
Oversea	Across the sea or ocean	Abroad, international
Overseas	Located across the sea or ocean	Foreign, international
Oversensitive	Excessively sensitive	Touchy, thin-skinned
Overserious	Excessively serious or grave	Solemn, stern
Oversewn	Sewn excessively or with too much stitching	Stitched, oversewed
Oversexed	Having excessive sexual desire	Libidinous, overly sexual
Overshot	Having exceeded a target or goal	Overreached, surpassed
Oversimplistic	Excessively simplified	Simplistic, reductive
Oversize	Larger than usual size	Big, large, bulky
Oversized	Made larger than normal	Large, big, ample
Overslow	Excessively slow	Sluggish, lethargic
Oversmoothed	Made overly smooth or polished	Polished, refined
Oversnowed	Covered with too much snow	Snow-covered, snow-laden
Oversocialized	Excessively accustomed to social norms	Overtrained, too polite
Oversoft	Too soft or gentle	Gentle, yielding
Oversolar	Exposed to too much sunlight	Sun-exposed, sunburned
Oversolicitous	Excessively concerned or attentive	Overattentive, anxious
Oversophisticated	Too complex or refined	Complex, over-elaborate
Oversparred	Engaged in too much sparring or argument	Overargued, overcontested
Overspecific	Too detailed or narrowly defined	Detailed, too particular
Overspeeding	Traveling at excessive speed	Racing, too fast
Overstated	Expressed in an exaggerated way	Exaggerated, inflated
Oversteered	Turned more than necessary	Overturned, overly turned
Overstimulated	Given too much stimulation	Hyper, overly excited
Overstrung	Extremely tense or nervous	Tense, high-strung
Overstuffed	Stuffed with too much material	Overfilled, bulky
Oversubscribed	Having more applicants than available space	Overbooked, full
Oversuspicious	Excessively suspicious or wary	Paranoid, doubtful
Overt	Done openly and not secret	Obvious, open
Over-the-counter	Available without a prescription	Nonprescription, general
Over-the-top	Excessive or extreme in style or behavior	Exaggerated, extreme
Overtight	Too tight or constricting	Snug, overly fitted
Overtired	Extremely tired	Exhausted, fatigued
Overtouristed	Having too many tourists	Overcrowded, congested
Overtroubled	Excessively worried or troubled	Distressed, stressed
Overtrusting	Too trusting or naïve	Gullible, too trusting
Overturnable	Capable of being overturned	Reversible, changeable
Overturned	Flipped or turned over	Upset, reversed
Overuniform	Excessively similar or standardized	Monotonous, uniform
Overvaliant	Excessively brave or courageous	Brave, fearless
Overwater	Supplied with too much water	Saturated, flooded
Overweening	Showing excessive pride or arrogance	Arrogant, conceited
Overweight	Above a healthy weight	Heavy, obese
Overwhelmed	Overpowered by something	Overcome, engulfed
Overwhelming	Extremely intense or powerful	Powerful, immense
Overwrought	Extremely anxious or agitated	Distressed, tense
Overzealous	Excessively enthusiastic	Fanatical, passionate
Ovid	Relating to the Roman poet Ovid	Classical, poetic
Oviform	Shaped like an egg	Oval, egg-shaped
Ovigerous	Carrying or bearing eggs	Egg-bearing, fertile
Oviparous	Reproducing by laying eggs	Egg-laying, egg-producing
Ovular	Relating to an ovule or egg cell	Egg-shaped, ovum-related
Ovulational	Relating to ovulation	Fertile, reproductive
Ower	One who owes something	Debtor, obligor
Owing	Yet to be paid or settled	Due, unpaid
Owlish	Resembling an owl, often in appearance	Wise-looking, round-eyed
Own	Belonging to oneself	Personal, individual
Owned	Possessed by someone	Controlled, held
Oxalic	Containing oxalic acid	Acidic, oxalate-rich
Oxblood	Dark red color resembling dried blood	Dark red, maroon
Oxeyed	Having large, round eyes	Round-eyed, wide-eyed
Ox-eyed	Having large, rounded eyes	Wide-eyed, doe-eyed
Oxonian	Relating to Oxford, especially the university	Oxford-related, scholarly
Oxyacetic	Containing or related to acetic acid with oxygen	Acidic, chemical
Oxygenic	Producing or containing oxygen	Oxygen-producing, oxygenated
Oxyntic	Relating to acid-secreting stomach cells	Acidic, gastric
Oxytocic	Inducing labor by stimulating uterine contractions	Labor-inducing, uterine-stimulating
Oyster	Relating to or resembling an oyster	Shellfish, marine
Oysterish	Resembling or tasting like an oyster	Briny, oceanic
Oysterless	Without oysters	Oyster-free, shellfish-free
Oysterlike	Similar to or resembling an oyster	Oysterish, shellfish-like
Oystery	Characteristic of or resembling an oyster	Briny, seafood-like
Ozone-friendly	Not harmful to the ozone layer	Eco-friendly, ozone-safe

Frequently Asked Questions About Adjectives That Start With "O"

What are some common adjectives that start with O?

Common adjectives starting with O include optimistic, outstanding, open-minded, orderly, and objective.

What are some positive adjectives that start with O?

Positive adjectives starting with O include outstanding, opulent, openhearted, optimistic, and obliging.

How can adjectives starting with O improve my writing?

Using adjectives like 'outstanding' and 'optimistic' can make descriptions more engaging and expressive in your writing.