Words That Start With 'O'

Find all the words in the English language that start with O.

There are 2,452 words that begin with O.
There are 5 abbreviations that begin with O.
There are 897 phrases that begin with O.
Top Scoring Words That Start With O
Rank Word Length Scrabble WWF WordFeud
1 Ozonize 7 25 26 25
2 Oxidize 7 24 24 20
3 Obloquy 7 21 23 23
4 Overjoy 7 20 22 22
5 Oxyacid 7 20 20 17
6 Oxyopia 7 19 19 16
7 Off-key 6 19 18 19
8 Oblique 7 18 21 20
9 Objects 7 18 22 22
10 Opalize 7 18 20 19

1 Letter Words That Start With 'O'

Abbreviations
O

2 Letter Words That Start With 'O'

Words
Of5 Oh5 Ok6 On2 Or2 Os2 Ow5 Ox9

3 Letter Words That Start With 'O'

Words
Oaf6 Oak7 Oar3 Oat3 Obi5 Oca5 Oda4 Odd5 Ode4 O'er3 Off9 Oft6 Ohm8 Oil3 Oka7 Ola3 Old4 Ole3 Olm5 One3 Ooh6 Opt5 Ora3 Orb5 Ore3 Ota3 Otc5 Our3 Out3 Ova6 Owe6 Owl6 Own6
Abbreviations
Oz.

4 Letter Words That Start With 'O'

Words
Oafs7 Oaks8 Oars4 Oast4 Oath7 Oats4 Obey9 Obit6 Oboe6 Odds6 Oder5 Odes5 Odin5 Odor5 Ogee5 Ogle5 Ogre5 Ohio7 Ohms9 Oils4 Oily7 Oink8 Okay11 Okeh11 Okey11 Okra8 Olds5 Olea4 Olen4 Oleo4 Olla4 Olms6 Ombu8 Omen6 Omit6 Omni6 Once6 Oner4 Ones4 Only7 Onto4 View more...
Phrases
One C On It Or So
Abbreviations
O.d. O.k.

5 Letter Words That Start With 'O'

Words
Oaken9 Oakum11 Oases5 Oasis5 Oaten5 Oaths8 Obeah10 Obese7 Obeys10 Obits7 Oboes7 Occur9 Ocean7 Ocher10 Ochre10 Octad8 Octal7 Octet7 Odder7 Oddly10 Odist6 Odium8 Odors6 Odour6 Offal11 Offer11 Often8 Ogive9 Ogled7 Ogler6 Ogles6 Ogres6 Ohare8 Ohmic12 Oiled6 Oiler5 Oinks9 Okapi11 Okays12 Oland6 Olden6 View more...
Phrases
Of Age On Air On Tap Op Art O Ring Out In Out Of Out To Own Up

6 Letter Words That Start With 'O'

Words
Oafish12 Oakley13 Obeche13 Obechi13 Obelia8 Obeyed12 Obiism10 Object17 Oblate8 Oblige9 Oblong9 Oboist8 Obolus8 Obsess8 Obtain8 Obtund9 Obtuse8 Occult10 Occupy15 Occurs10 Oceans8 Ocelot8 Ochres11 O'clock14 Octane8 Octant8 Octave11 Octavo11 Octets8 Octroi8 Ocular8 Oculus8 Oddest8 Oddish11 Oddity11 Oddjob17 Odd-job17 Odds-on8 Odelia7 Odious7 Odiums9 View more...
Phrases
Of Late Oil Nut Oil Rig Old Age Old Bag Old Boy Old Man On Base On Fire On Hand Only If View more...

7 Letter Words That Start With 'O'

Words
Oarfish13 Oarlock13 Oarsman9 Oarsmen9 Oatcake13 Oatmeal9 Obelion9 Obelisk13 Obesity12 Obeying13 Objects18 Obliged11 Obliger10 Obliges10 Oblique18 Oblongs10 Obloquy21 Obovate12 Obscene11 Obscure11 Observe12 Obtains9 Obtrude10 Obverse12 Obviate12 Obvious12 Ocarina9 Occiput13 Occlude12 Occults11 Oceanic11 Ocellus9 Ocelots9 Octagon10 Octanes9 Octaves12 Octavia12 Octette9 October11 Octopod12 Octopus11 View more...
Phrases
Oak Fern Oak Tree Odd Fish Offer Up Off Year Oil Cake Oil Lamp Oil Meal Oil Palm Oil Pump Oil Well View more...

8 Letter Words That Start With 'O'

Words
Oatcakes14 Obduracy16 Obdurate11 Obedient11 Obelisks14 Obituary13 Objected20 Objector19 Oblation10 Obligate11 Obligato11 Obliging12 Obliqued20 Oblivion13 Obscured13 Obscurer12 Obscures12 Observed14 Observer13 Observes13 Obsessed11 Obsesses10 Obsidian11 Obsolete10 Obstacle12 Obstruct12 Obtained11 Obtruded12 Obturate10 Obtusely13 Obviated14 Obviates13 Occasion12 Occident13 Occluded14 Occludes13 Occupant14 Occupied15 Occupier14 Occupies14 Occurred13 View more...
Phrases
Oak Apple Of Course Off And On Off Guard Of Import Ogee Arch Oil Color Oil Gland Oil Paint Oil Shale Oil Slick View more...

9 Letter Words That Start With 'O'

Words
Oarswoman14 Obbligato14 Obedience14 Obeisance13 Obfuscate16 Objectify26 Objecting21 Objection20 Objective23 Objectors20 Objurgate19 Obligated13 Obliquely23 Obliquity23 Oblivious14 Obnoxious18 Obscenely16 Obscenity16 Obscurely16 Obscurest13 Obscuring14 Obscurity16 Observant14 Observers14 Observing15 Obsessing12 Obsession11 Obsessive14 Obsolesce13 Obstacles13 Obstetric13 Obstinacy16 Obstinate11 Obstipate13 Obstructs13 Obstruent11 Obtaining12 Obtention11 Obtruding13 Obtrusive14 Obturator11 View more...
Phrases
Oak Blight Oast House Objet D'art Ocean Pout Ocean Trip Odd Fellow Odd-job Man Odd Man Out Of All Time Of A Sudden Office Boy View more...
Abbreviations
On The Q.T.

10 Letter Words That Start With 'O'

Words
Obdurately16 Obediently16 Obfuscated18 Obfuscates17 Obituaries12 Objections21 Objectives24 Objectless21 Oblateness12 Obligation13 Obligatory16 Obligingly17 Obliterate12 Oblongness13 Obnubilate14 Obsequious21 Observable17 Observably20 Observance17 Obsessions12 Obstetrics14 Obstinance14 Obstructed15 Obstructer14 Obstructor14 Obtainable14 Obtainment14 Obtuseness12 Occasional14 Occasioned15 Occidental15 Occupation16 Occurrence16 Oceanfront15 Oceangoing14 Oceanology16 Ochlocracy22 Ochronosis15 Octahedral16 Octahedron16 Octangular13 View more...
Phrases
Object Ball Object Code Object Lens Oblong Leaf Oboe D'amore Obtuse Leaf Occult Arts Ocean Floor Ocean Liner Ocean Perch Octal Digit View more...

11 Letter Words That Start With 'O'

Words
Oarsmanship18 Obfuscation18 Obfuscatory21 Objectified26 Objectively28 Objectivity28 Objurgation21 Obligations14 Obliqueness22 Obliterable15 Obliterated14 Obliterates13 Obliterator13 Obnoxiously23 Obscenities15 Obscuration15 Obscureness15 Obscurities15 Observables18 Observances18 Observantly19 Observation16 Observatory19 Observingly20 Obsessional13 Obsessively19 Obsessivity19 Obsolescent15 Obstetrical15 Obstinately16 Obstipation15 Obstructing16 Obstruction15 Obstructive18 Obtrusively19 Obviousness16 Occasioning16 Occultation15 Occupancies19 Occupations17 Occurrences17 View more...
Phrases
Oak Chestnut Obesity Diet Object Glass Oblique Case Obovate Leaf Obtrude Upon Obtuse Angle Occam's Razor Ocean Bottom Oceanic Bird Ochna Family View more...

12 Letter Words That Start With 'O'

Words
Oblanceolate16 Obligational15 Obligatorily18 Obligingness16 Obliterating15 Obliteration14 Obscurantism18 Obscurantist16 Obsequiously26 Observations17 Observatorys20 Obsolescence18 Obsoleteness14 Obstetrician16 Obstreperous16 Obstructions16 Occasionally19 Occupational18 Oceanography23 Octogenarian15 Octosyllabic21 Octosyllable19 Oesophagitis18 Office-bearer22 Officeholder24 Officerships25 Officialness20 Oldfashioned20 Old-fashioned20 Oligarchical20 Oligodactyly22 Oligodendria15 Oligospermia17 Olive-colored18 Omnipresence18 One-billionth17 One-hundredth20 Oneiromancer16 One-millionth17 Onesidedness14 One-sixteenth22 View more...
Phrases
Obiter Dictum Object Lesson Oblique Angle Oboe Da Caccia Observed Fire Obstacle Race Ocean Current Oceanic Abyss Ocean Sunfish Ockham's Razor Octane Number View more...

13 Letter Words That Start With 'O'

Words
Objectionable26 Objectionably29 Objectiveness27 Oblique-angled26 Obliviousness18 Obnoxiousness22 Observability23 Observational18 Observatories18 Obsessionally18 Obsessiveness18 Obstetricians17 Obstructively23 Obtrusiveness18 Occidentalise18 Occidentalism20 Occidentalize27 Oceanographer21 Oceanographic23 Octogenarians16 Odontoglossum17 Offensiveness22 Officiousness21 Oleomargarine16 Olive-coloured19 One-thousandth20 One-trillionth16 Onomatopoetic19 Ontologically19 Opacification22 Operationally18 Ophthalmology27 Opportuneness17 Opportunistic19 Opportunities17 Optimisations17 Orange-colored17 Orchestrating19 Orchestration18 Organisations14 Ornamentalism17 View more...
Phrases
Oatmeal Cookie Obedient Plant Objective Case Objective Lens Object Program Oblong Woodsia Obturator Vein Occipital Bone Occipital Lobe Occipital Vein Occluded Front View more...

14 Letter Words That Start With 'O'

Words
Obsequiousness25 Obstreperously21 Obstructionism20 Obstructionist18 Occupationally23 Oceanographers22 Oesophagoscope24 Off-the-shoulder27 Oleaginousness15 Oligomenorrhea20 Omnium-gatherum24 Omphaloskepsis27 Onchocerciasis23 One-dimensional17 One-sixty-fourth30 Onomatopoeical20 Openhandedness21 Openmindedness20 Operationalism18 Operationalist16 Ophthalmectomy31 Ophthalmoscope28 Ophthalmoscopy31 Oppressiveness21 Optimistically23 Optoelectronic20 Orange-coloured18 Orange-flowered22 Orchestrations19 Organification20 Organisational15 Organizational24 Ornithological20 Ornithologists18 Orthographical25 Orthomolecular21 Orthomyxovirus32 Orthophosphate27 Ostentatiously17 Osteoarthritis17 Osteochondroma22 View more...
Phrases
Obedience Plant Object Language Oblique Bandage Obtuse Triangle Occipital Gyrus Oculus Sinister Odd-pinnate Leaf Oedipal Complex Oedipus Complex Office Building Offset Printing View more...

15 Letter Words That Start With 'O'

Words
Objectification31 Observationally23 Obstructiveness22 Oligodendrocyte23 Oligodendroglia19 Oligosaccharide24 Omnidirectional20 One-thirty-second24 Ophthalmologist26 Ophthalmoplegia28 Opisthognathous24 Opisthorchiasis25 Organophosphate26 Overachievement28 Overbearingness21 Overcommitments26 Overcomplicated27 Over-embellished26 Overfamiliarity26 Overgeneralised20 Overincredulous21 Overrepresented21 Oversensitivity24 Oversimplifying29 Overutilisation18 Overutilization27 Oxyphenbutazone41
Phrases
Object Of The Verb Oblique Triangle Observation Dome Observation Post Obstetrical Toad Occipital Cortex Ocellated Turkey Octanedioic Acid Oculomotor Nerve Odd-toed Ungulate Odontoid Process View more...

16 Letter Words That Start With 'O'

Words
Obstreperousness20 Old-fashionedness24 Old-man-of-the-woods29 One-quadrillionth29 One-quintillionth28 One-ten-thousandth23 Ophthalmologists27 Organisationally20 Organizationally29 Orthographically30 Ostentatiousness16 Otherworldliness23 Otolaryngologist21 Overcompensation25 Overenthusiastic24 Overexploitation28 Overgeneralising21 Oxyphencyclimine40
Phrases
Oakleaf Goosefoot Oat Cell Carcinoma Oblanceolate Leaf Obligate Anaerobe Observation Tower Obstructive Shock Octadecanoic Acid Oesophageal Veins Off-axis Reflector Official Document Official Emissary View more...

17 Letter Words That Start With 'O'

Words
Objectionableness30 One-dimensionality23 Opportunistically26 Outward-developing28 Oversensitiveness23
Phrases
Obidoxime Chloride Object Recognition Observer's Meridian Occupational Group Occupation Licence Occupation License Octal Number System Oesophageal Reflux Offset Lithography Offsetting Balance Off The Beaten Track View more...

18 Letter Words That Start With 'O'

Words
Order-Chenopodiales27 Overcapitalisation25 Overcapitalization34 Oversimplification30 Oxidation-reduction29
Phrases
Oak-leaved Goosefoot Occupational Hazard Oil-industry Analyst Olfactory Sensation On An Irregular Basis One Thousand Million Open-air Marketplace Operating Procedure Operating Statement Operations Research Orange Horseshoe Bat View more...

19 Letter Words That Start With 'O'

Words
Obsessive-compulsive33 One-hundred-millionth29 Otorhinolaryngology30 Oversimplifications31
Phrases
Obstetrical Delivery Occupational Disease Occupational Therapy Old Man Of The Mountain Olfactory Impairment Olfactory Perception On An Individual Basis One Hundred Fifty-five One Hundred Forty-five One Hundred Sixty-five One Thousand Thousand View more...

20 Letter Words That Start With 'O'

Words
One-hundred-thousandth32 Oophorosalpingectomy35
Phrases
Object Of A Preposition Obstruction Of Justice Obtuse-angled Triangle Oceanic Whitetip Shark Omnidirectional Range One Hundred Thirty-five One Hundred Twenty-five On The Spur Of The Moment Ophthalmia Neonatorum Orange Mushroom Pimple Order Of Saint Benedict View more...

21 Letter Words That Start With 'O'

Words
Otorhinolaryngologist29
Phrases
Occipital Protuberance Occipitomastoid Suture Octal Numeration System One Hundred Seventy-five Onion Yellow-dwarf Virus Operating Instructions Oral Contraceptive Pill Oral Poliovirus Vaccine Order Mantophasmatodea Ordinary Life Insurance Ornithischian Dinosaur View more...

22 Letter Words That Start With 'O'

Phrases
Object-oriented Database Omnidirectional Antenna One-dimensional Language One-flowered Wintergreen Opportunistic Infection Orange-juice Concentrate Orthomorphic Projection Orthostatic Hypotension Osteogenesis Imperfecta Over-the-counter Medicine Over The Counter Security View more...

23 Letter Words That Start With 'O'

Phrases
Osteosclerosis Congenita

24 Letter Words That Start With 'O'

Phrases
Object-oriented Programing Oesophagogastric Junction One Million Million Million Open-end Investment Company Oxidative Phosphorylation

25 Letter Words That Start With 'O'

Phrases
Object-oriented Programming Omnidirectional Radio Range Organic Light-emitting Diode Organophosphate Nerve Agent

26 Letter Words That Start With 'O'

Phrases
Oblique Vein Of The Left Atrium

27 Letter Words That Start With 'O'

Phrases
Obsessive-compulsive Disorder Oxidation-reduction Indicator

30 Letter Words That Start With 'O'

Phrases
Obsessive-compulsive Personality Occupational Safety And Health Act

32 Letter Words That Start With 'O'

Phrases
Object-oriented Programing Language Oculopharyngeal Muscular Dystrophy

33 Letter Words That Start With 'O'

Phrases
Object-oriented Programming Language

38 Letter Words That Start With 'O'

Phrases
Object-oriented Database Management System
Words That Start With
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