Here is a complete list of adjectives that start with ‘O.’ There are 917 adjectives in these tables starting with the letter ‘O.’ As there are more than a hundred adjectives, we have not provided a definition here. Please visit Merriam-Webster dictionary for a meaning.
Moreover, there are more than 600,000 English words. But, most of those words are no longer used in modern literature. For example, the Merriam-Webster dictionary recognizes only about 200,000 words. Out of those 200,000; around 34,000 are adjectives.
Adjectives Adjectives Oahuan Oaken Oaky Oary Oasal Oasitic Oaten Obbligato Obclavate Obcompressed Obconic Obcordate Obcuneate Obdeltoid Obdiplostemonous Obdurate Obdure Obedient Obediential Obeliscal Obeliscoid Obese Obesogenic Obeyable Obfusc Obfuscable Obfusticated Obital Obitual Object Objectable Objectifiable Objectionable Objectional Objectival Objective Objurgative Oblanceolate Oblate Oblational Oblatory Obligable Obligate Obligational Obligative Obligatory Obliging Obligistic Oblique Obliquitous Obliterable Obliterative Oblivial Oblivious Oblong Oblongatal Oblongated Oblongish Obloquial Obloquious Obnoxious Obomegoid Obovate Obovoid Obpyramidal Obpyriform Obreptitious Obrotund Obround Obscene Obscurant Obscurative Obscure Obsequent Obsequial Obsequious Observable Observant Observation Observative Observatorial Obsessed Obsessive Obsidional Obsidionary Obsidious Obsolescent Obsolete Obstetric Obstinate Obstreperous Obstruse Obtect Obtrusive Obturbinate Obtuse Obumbrant Obumbrate Obvallate Obverse Obviable Obviative Obvious Obvolute Occasional Occasionalistic Occidental Occipital Occipitomastoid Occludent Occlusal Occlusive Occult Occupational Occupative Occupiable Occurrent Oceangoing Oceanic Oceanodromous
Adjectives Adjectives Ocellated Ocellocular Ocherish Ochery Ochoan Ochraceous Ochroid Ocreate Octahedral Octal Octamerous Octangular Octapodic Octarch Octastrophic Octastyle Octatonic Octaval Octennial Octodont Octofoil Octogenary Octoid Octonary Octonocular Octopal Octopean Octophthalmous Octoploid Octopodous Octostiate Octosyllabic Octuple Octuplicate Ocular Oculate Oculauditory Oculomotor Odal Odd Oddish Odic Odiferous Odinic Odious Odontocete Odontophoral Odontophorous Odontorhynchous Odorate Odoriferous Odorous Odylic Odyssean Oecophorid Oedemerid Oedipal Oedipean Oedipus Off Offbeat Offcast Offensible Offensive Offerable Offgrade Offhand Offhanded Officeless Officerless Official Officiary Officinal Officious Offish Offshore Offtype Ogeed Ogival Ogived Ogmic Ogygian Oidioid Oikomonad Oiled Oilless Oilproof Oilskinned Oiltight Oily Okvik Old Olden Oldfangled Oldish Oldowan Ole Oleaceous Oleaginous Olecranal Oleiferous Olent Oleocalcareous Oleomargaric Oleous Oleraceous Olfactive Olfactory Olid Oligarchal Oligarchic Oligidic Oligocene Oligochaetological Oligomyodian Oligonephric Oligophagous Oligopod Oligopyrene Oligosaprobic
Adjectives Adjectives Oligospermatic Oligotrophic Oligotropic Oligozoic Olitory Olivaceous Olive Oliverian Olivescent Oliviferous Oliviform Olympian Olympic Ombrophilous Ombrophobous Ombré Omega Omegoid Ominous Omissible Omissive Ommateal Omnibus Omnicompetent Omnidirectional Omnifarious Omnific Omnificent Omnigenous Omnilegent Omniphibious Omnipotent Omnipresent Omniscient Omnisexual Omnivorous Omphaloid On Onboard Once Oncogenic Oncoming One Onefold Oneiric Oneirocritical Oneota Onerous Onetime Ongoing Onium Onliest Online Only Onomasiologic Onomastic Onshore Ontic Onto Ontogenetic Ontological Onward Onychoid Onymous Ooecial Oofy Oogamous Ooid Ookinetic Oological Oophagous Oosporiferous Oozy Opacous Opalescent Opalesque Opaline Opalinid Opaloid Opaque Open Open-mouthed Openband Opencast Openhanded Openhearted Openside Operable Operant Operatable Operatic Operating Operational Operationistic Operative Opercled Opercular Operculate Operose Operous Ophic Ophidian Ophidiid Ophidioid Ophiological Ophiomorphic Ophiophagous Ophitic Ophiurid Ophthalmic Ophthalmometric Opiate Opiatic Opinable Opinative Opiniative Opiniatre Opinionable Opinional Opinionate
Adjectives Adjectives Opinionated Opinionative Opioid Opiparous Opisthocoelian Opisthocoelous Opisthodetic Opisthodont Opisthogastric Opisthoglyph Opisthogoneate Opisthogyrate Opisthorchiid Opisthosomal Opisthotic Oppidan Oppilative Opponent Opportune Opportunistic Opposable Opposed Opposeless Opposite Oppositionary Oppositionless Oppositious Oppositive Oppressed Oppressible Oppressive Opprobrious Oppugnant Opsonic Optable Optative Optic Optical Optimal Optimistic Optimum Optional Optionary Optive Optokinetic Opulent Opuntioid Opuscular Oracular Oraculous Oral Orange Orangey Orangish Oranian Oratorial Oratorical Orbic Orbicular Orbiculate Orbital Orbitoid Orbless Orby Orchestiid Orchestral Orchestraless Orchestric Orchidaceous Order Ordered Orderly Ordinable Ordinal Ordinant Ordinary Ordovician Oreless Oreophasine Organal Organic Organical Organistic Organization Organizational Organized Organless Organochlorine Organogenic Organographic Organoleptic Organologic Organometallic Organophilic Organophosphorus Organoplastic Organosilicon Orgasmic Orgastic Orgiastic Orgulous Orient Oriental Orientated Oriented Origenian Origenic Origenist Original Originant Originary Originative Orinasal Orleanian Ornamental Ornate Ornery Ornithic Ornithodelphian Ornithogaean
Adjectives Adjectives Ornithoid Ornithomyzous Ornithophilous Ornithopodous Ornithorhynchous Ornithoscopic Ornithotic Ornithotomical Oroanal Orobanchaceous Orobathymetric Orocratic Orographic Orohydrographic Orohydrologic Orological Orometric Oropharyngeal Orophilous Orotund Orphean Orphic Orpit Orra Orthal Orthian Orthic Ortho Orthoceratoid Orthochromatic Orthoclastic Orthodolichocephalic Orthodox Orthodoxal Orthodoxical Orthogenic Orthogonal Orthograde Orthographic Orthometopic Orthometric Orthomolecular Orthomorphic Orthonormal Orthopanchromatic Orthopedic Orthopteral Orthopterological Orthorhombic Orthoscopic Orthosomatic Orthostatic Orthostichous Orthostyle Orthosymmetric Orthotic Orthotone Orthotropic Orthotropous Ortygian Orwellian Oryctognostic Oryctologic Oryzivorous Osagian Oscine Oscinine Oscitant Osculant Oscular Osiered Osirian Osiride Osmagogue Osmatic Osmic Osmiophil Osmotactic Osmotic Osmous Osphradial Osphretic Osseous Ossianic Ossiculate Osteal Ostensible Ostensive Ostentatious Ostentative Ostentive Osteodermatous Osteofibrous Osteogenic Osteoglossid Osteoid Osteolepid Osteolepiform Osteolepoid Osteologic Osteostracan Ostiate Ostiolar Ostiolate Ostomatid Ostracean Ostraceous Ostreiform Ostreoid Ostreophagous Otacoustic Otaheitan Other Otherguess Otherwise Otherworldly Otiorhynchid Otiose Otitid Otoconial
Adjectives Adjectives Ototoxic Ottoman Ottomanean Ottomanic Ottonian Otukian Our Ourie Out Outblowing Outboard Outbond Outbound Outbreathed Outcast Outdated Outdoor Outdoorsy Outer Outerly Outermost Outflaring Outflung Outgiving Outgliding Outgoing Outlandish Outlinear Outlying Outmoded Outmost Outrageous Outriggered Outright Outré Outsetting Outside Outsize Outspent Outspoken Outspread Outstanding Outstate Outsucken Outthrust Outward Outworn Ouvert Oval Ovaloid Ovarian Ovate Ovational Ovendry Ovenproof Over Overabstract Overactive Overage Overaggressive Overalert Overall Overalled Overambitious Overamplified Overanalytical Overanimated Overanxious Overarching Overarm Overassertive Overattentive Overbaked Overbearing Overbejeweled Overberg Overblown Overbold Overbought Overbowed Overbrief Overbright Overbroad Overbulky Overbusy Overcareful Overcast Overcautious Overceiling Overchurched Overcivilized Overclean Overclear Overcomplex Overcomplicated Overconcerned Overconfident Overconscientious Overconscious Overconservative Overcredulous Overcritical Overcurious Overdaring Overdated Overdear Overdelicate Overdemanding Overdependent Overdetermined Overdiligent Overdramatic Overdrawn Overdrifted Overdriven Overdry Overdue Overeager Overearnest Overeducated
Adjectives Adjectives Overelaborate Overemotional Overemphatic Overenamored Overenergetic Overenrolled Overentertained Overenthusiastic Overequipped Overexcited Overexplicit Overextravagant Overexuberant Overfamiliar Overfastidious Overfat Overfleshed Overfond Overfull Overfussy Overgenerous Overglaze Overground Overgrown Overhand Overhappy Overhasty Overhead Overheated Overheavy Overimaginative Overindulgent Overinformed Overingenious Overinsistent Overinsured Overintense Overintricate Overjoyed Overkind Overknee Overladen Overland Overlarge Overlavish Overleave Overlength Overliberal Overliteral Overliterary Overlong Overlooked Overloud Overlush Overlusty Overmannered Overmastering Overmature Overmighty Overmodest Overmost Overmountain Overmuch Overmuscled Overnice Overnight Overobvious Overopinionated Overorchestrated Overornate Overparted Overparticular Overpast Overpeopled Overpick Overpitched Overpotent Overprecise Overprepared Overprivileged Overproduced Overproof Overqualified Overquick Overrank Overrated Overready Overrefined Overrepresented Overrich Overriding Overrigid Overripe Oversanded Oversanguine Overscale Overscrupulous Overseas Oversensitive Overserious Overserved Oversexed Oversharp Overshifted Overshot Overside Oversimple Oversimplistic Oversize Overslung Oversnow Oversoft Oversold Oversolicitous Oversophisticated Overspeed Oversquare Overstimulated Overstored Overstrength
Adjectives Adjectives Overstrict Overstrung Oversubtle Oversuspicious Oversweet Overt Overtalkative Overtheatrical Overthin Overthwart Overtired Overviolent Overvivid Overwater Overweary Overweathered Overweening Overweight Overwhelmed Overwhelming Overwinter Overwise Overwordy Overwrought Overyear Overzealous Ovicular Ovine Oviparous Ovistic Ovoid Ovotesticular Ovoviviparous Ovularian Ovulate Ovulatory Ovuliferous Owing Owlish Owllike Owly Own Ownerless Oxbridge Oxeote Oxidable Oxidimetric Oxidulated Oxlike Oxo Oxy Oxyacetylene Oxybiotic Oxycalcium Oxychromatic Oxydactyl Oxydiact Oxygas Oxygenic Oxygenous Oxygnathous Oxyhydrogen Oxyluminescent Oxymuriatic Oxypetalous Oxyphilic Oxyrhynch Oxyrhynchous Oxytocic Oxytone Oxytonic Oxytylotate Oxyuroid Oystered Oystery Ozoniferous Ozonous
