12-letter words starting with O
Embark on a linguistic journey with words that begin with the letter O. This section showcases how O at the start shapes the identity and sound of various words. From commonly used terms to rare finds, explore the diverse range of words that start with O, enriching your vocabulary and appreciation for language.
| Word | Points | Definition | Sentence example |
|---|---|---|---|
| organization | 22 | the persons (or committees or departments etc.) who make up a body for the purpose of administering something | - |
| occasionally | 19 | sporadically and infrequently | he was arrogant and occasionally callous |
| overwhelming | 24 | very strong; urgently felt | overwhelming joy |
| organisation | 13 | the persons (or committees or departments etc.) who make up a body for the purpose of administering something | - |
| occupational | 18 | of or relating to the activity or business for which you are trained | occupational hazard |
| orchestrated | 18 | arranged for performance by an orchestra | - |
| overpowering | 21 | so strong as to be irresistible | an overpowering need for solitude |
| orthodontist | 16 | a dentist specializing in the prevention or correction of irregularities of the teeth | - |
| outstretched | 18 | fully extended especially in length | a kitten with one paw outstretched |
| ostentatious | 12 | intended to attract notice and impress others | an ostentatious sable coat |
| overestimate | 17 | a calculation that results in an estimate that is too high | - |
| osteoporosis | 14 | abnormal loss of bony tissue resulting in fragile porous bones attributable to a lack of calcium; most common in postmenopausal women | - |
| obstetrician | 16 | a physician specializing in obstetrics | - |
| otherworldly | 22 | existing outside of or not in accordance with nature | - |
| outrageously | 16 | to an extravagant or immoderate degree | - |
| overstepping | 20 | - | - |
| oceanography | 23 | the branch of science dealing with physical and biological aspects of the oceans | - |
| overreaction | 17 | an excessive reaction; a reaction with inappropriate emotional behavior | - |
| obliteration | 14 | destruction by annihilating something | - |
| obsolescence | 18 | the process of becoming obsolete; falling into disuse or becoming out of date | a policy of planned obsolescence |
| obscurantism | 18 | a deliberate act intended to make something obscure | - |
| orthodontics | 18 | the branch of dentistry dealing with the prevention or correction of irregularities of the teeth | - |
| osteosarcoma | 16 | malignant bone tumor; most common in children and young adults where it tends to affect the femur | - |
| overdramatic | 20 | - | - |
| overspending | 19 | - | - |
| oligarchical | 20 | of or relating to or supporting or characteristic of an oligarchy | - |
| orthopaedics | 20 | the branch of medical science concerned with disorders or deformities of the spine and joints | - |
| overburdened | 19 | heavily burdened with work or cares | overburdened social workers |
| oversleeping | 18 | - | - |
| orienteering | 13 | - | - |
| overachiever | 23 | a student who attains higher standards than the IQ indicated | - |
| overeducated | 19 | - | - |
| overindulged | 18 | - | - |
| ordinariness | 13 | the quality of being commonplace and ordinary | - |
| overexposure | 24 | the act of exposing film to too much light or for too long a time | - |
| overreaching | 21 | revealing excessive self-confidence; reaching for the heights | - |
| oversimplify | 25 | make too simple | Don't oversimplify the instructions |
| obscurantist | 16 | a person who is deliberately vague | - |
| onomatopoeia | 16 | using words that imitate the sound they denote | - |
| orchestrator | 17 | an arranger who writes for orchestras | - |
| oscilloscope | 18 | electronic equipment that provides visual images of varying electrical quantities | - |
| ossification | 17 | hardened conventionality | - |
| osteogenesis | 13 | - | - |
| outplacement | 18 | - | - |
| overgenerous | 16 | very generous | - |
| obligatorily | 18 | in a manner that cannot be evaded | - |
| obstreperous | 16 | boisterously and noisily aggressive | kept up an obstreperous clamor |
| octogenarian | 15 | being from 80 to 89 years old | - |
| omnipresence | 18 | the state of being everywhere at once (or seeming to be everywhere at once) | - |
| optimization | 25 | the act of rendering optimal | the simultaneous optimization of growth and profitability |
| overcautious | 17 | unnecessarily cautious | sometimes it doesn't pay to be overcautious in business |
| overexertion | 22 | excessive exertion; so much exertion that discomfort or injury results | - |
| overinflated | 19 | - | - |
| overshooting | 19 | - | - |
| oafishnesses | 18 | - | - |
| oarsmanships | 19 | - | - |
| obcompressed | 21 | - | - |
| obdurateness | 15 | - | - |
| obedientiary | 18 | - | - |
| obfuscations | 19 | - | - |
| objectifying | 30 | - | - |
| objectivated | 27 | - | - |
| objectivates | 26 | - | - |
| objectivised | 27 | - | - |
| objectivises | 26 | - | - |
| objectivisms | 28 | - | - |
| objectivists | 26 | - | - |
| objectivized | 36 | - | - |
| objectivizes | 35 | - | - |
| objurgations | 22 | - | - |
| oblanceolate | 16 | (of a leaf shape) having a broad rounded apex and a tapering base | - |
| oblatenesses | 14 | - | - |
| obligational | 15 | relating or constituting or qualified to create a legal or financial obligation | obligational authority |
| obligingness | 16 | a disposition or tendency to yield to the will of others | - |
| obliquations | 23 | - | - |
| obliterating | 15 | - | - |
| obliterative | 17 | - | - |
| obliterators | 14 | - | - |
| obliviscence | 21 | - | - |
| obmutescence | 20 | - | - |
| obnubilating | 17 | - | - |
| obnubilation | 16 | - | - |
| obreptitious | 16 | - | - |
| obscurations | 16 | - | - |
| obscurements | 18 | - | - |
| obsecrations | 16 | - | - |
| obsequiously | 26 | in an obsequious manner | she acts obsequiously toward her boss |
| observancies | 19 | - | - |
| observations | 17 | - | - |
| obsessionist | 14 | - | - |
| obsignations | 15 | - | - |
| obsoleteness | 14 | the property of being out of date and not current | - |
| obstipations | 16 | - | - |
| obstreperate | 16 | - | - |
| obstrictions | 16 | - | - |
| obstropalous | 16 | - | - |
| obstropulous | 16 | - | - |
| obstructions | 16 | - | - |
| obstructives | 19 | - | - |
| obtemperated | 19 | - | - |
| obtemperates | 18 | - | - |
| obtestations | 14 | - | - |
| obtruncating | 17 | - | - |
| obtusenesses | 14 | - | - |
| obumbrations | 18 | - | - |
| occidentally | 20 | - | - |
| occultations | 16 | - | - |
| occultnesses | 16 | - | - |
| oceanologies | 15 | - | - |
| oceanologist | 15 | - | - |
| ochlocracies | 21 | - | - |
| ochlophobiac | 26 | - | - |
| ochlophobias | 24 | - | - |
| ochlophobics | 26 | - | - |
| ochroleucous | 19 | - | - |
| octahedrally | 21 | - | - |
| octahedrites | 18 | - | - |
| octapeptides | 19 | - | - |
| octaploidies | 17 | - | - |
| octastichons | 19 | - | - |
| octastichous | 19 | - | - |
| octastrophic | 21 | - | - |
| octillionths | 17 | - | - |
| octogenaries | 15 | - | - |
| octopetalous | 16 | - | - |
| octosepalous | 16 | - | - |
| octostichous | 19 | - | - |
| octosyllabic | 21 | having or characterized by or consisting of eight syllables | - |
| octosyllable | 19 | a verse line having eight syllables or a poem of octosyllabic lines | - |
| octuplicates | 18 | - | - |
| odiousnesses | 13 | - | - |
| odontoblasts | 15 | - | - |
| odontogenies | 14 | - | - |
| odontographs | 19 | - | - |
| odontography | 22 | - | - |
| odontologies | 14 | - | - |
| odontologist | 14 | - | - |
| odontomatous | 15 | - | - |
| odontophobia | 20 | - | - |
| odontophoral | 18 | - | - |
| odontophoran | 18 | - | - |
| odontophores | 18 | - | - |
| odorimetries | 15 | - | - |
| oenophilists | 17 | - | - |
| oesophagitis | 18 | inflammation of the esophagus; often caused by gastroesophageal reflux | - |
| oesophaguses | 18 | - | - |
| offendresses | 19 | - | - |
| officeholder | 24 | someone who is appointed or elected to an office and who holds a position of trust | - |
| officialdoms | 23 | - | - |
| officialeses | 20 | - | - |
| officialisms | 22 | - | - |
| officialties | 20 | - | - |
| officiations | 20 | - | - |
| offishnesses | 21 | - | - |
| offscourings | 21 | - | - |
| olallieberry | 17 | - | - |
| oleaginously | 16 | - | - |
| oleandomycin | 20 | - | - |
| oleographies | 18 | - | - |
| oleomargarin | 15 | - | - |
| oleoresinous | 12 | - | - |
| olericulture | 14 | - | - |
| olfactometer | 19 | - | - |
| olfactometry | 22 | - | - |
| olfactronics | 19 | - | - |
| oligochaetes | 18 | - | - |
| oligochromes | 20 | - | - |
| oligopeptide | 18 | - | - |
| oligophagies | 19 | - | - |
| oligophagous | 19 | - | - |
| oligopolists | 15 | - | - |
| oligopsonies | 15 | - | - |
| oligospermia | 17 | insufficient spermatozoa in the semen | - |
| oligotrophic | 20 | - | - |
| ombrophilous | 21 | - | - |
| ombrophobous | 23 | - | - |
| ombudsperson | 19 | - | - |
| omissiveness | 17 | - | - |
| ommatophores | 21 | - | - |
| omnificences | 21 | - | - |
| omniparities | 16 | - | - |
| omnipotences | 18 | - | - |
| omnipotently | 19 | - | - |
| omnisciences | 18 | - | - |
| omnisciently | 19 | - | - |
| omnishambles | 21 | - | - |
| omnivorously | 20 | - | - |
| omphalomancy | 26 | - | - |
| oncogenicity | 20 | - | - |
| oncornavirus | 17 | - | - |
| oneirocritic | 16 | - | - |
| oneirodynias | 16 | - | - |
| oneirologies | 13 | - | - |
| oneiromancer | 16 | someone who divines through the interpretation of dreams | - |
| onomasiology | 18 | - | - |
| onomastician | 16 | - | - |
| onomasticons | 16 | - | - |
| onomatopoeic | 18 | (of words) formed in imitation of a natural sound | onomatopoeic words are imitative of noises |
| onychophoran | 25 | any of numerous velvety-skinned wormlike carnivorous animals common in tropical forests having characteristics of both arthropods and annelid worms | - |
| oophorectomy | 24 | surgical removal of one of both ovaries | - |
| oophoritises | 17 | - | - |
| opalescences | 18 | - | - |
| opalescently | 19 | - | - |
| opaquenesses | 23 | - | - |
| opeidoscopes | 19 | - | - |
| openhandedly | 22 | - | - |
| operatically | 19 | - | - |
| operationism | 16 | - | - |
| operationist | 14 | - | - |
| operatorless | 14 | - | - |
| ophicalcites | 21 | - | - |
| ophidiariums | 20 | - | - |
| ophiolatries | 17 | - | - |
| ophiolatrous | 17 | - | - |
| ophiological | 20 | - | - |
| ophiologists | 18 | - | - |
| ophiomorphic | 26 | - | - |
| ophiophagous | 23 | - | - |
| ophiophilist | 22 | - | - |
| ophthalmists | 22 | - | - |
| ophthalmitis | 22 | severe conjunctivitis | - |
| opinionately | 17 | - | - |
| opinionating | 15 | - | - |
| opinionative | 17 | obstinate in your opinions | - |
| opinionators | 14 | - | - |
| opisthodomoi | 20 | - | - |
| opisthodomos | 20 | - | - |
| opisthograph | 23 | - | - |
| opisthotonic | 19 | - | - |
| opisthotonos | 17 | severe spasm in which the back arches and the head bends back and heels flex toward the back | - |
| opotherapies | 19 | - | - |
| oppignerated | 18 | - | - |
| oppignerates | 17 | - | - |
| oppignorated | 18 | - | - |
| oppignorates | 17 | - | - |
| opportunisms | 18 | - | - |
| opportunists | 16 | - | - |
| opposability | 21 | - | - |
| oppositeness | 16 | the relation between opposed entities | - |
| oppositional | 16 | - | - |
| oppressingly | 20 | - | - |
| oppressively | 22 | in a heavy and oppressive way | it was oppressively hot in the office |
| oppugnancies | 19 | - | - |
| opsonisation | 14 | process whereby opsonins make an invading microorganism more susceptible to phagocytosis | - |
| opsonization | 23 | process whereby opsonins make an invading microorganism more susceptible to phagocytosis | - |
| optimalising | 17 | - | - |
| optimalities | 16 | - | - |
| optimalizing | 26 | - | - |
| optimisation | 16 | the act of rendering optimal | - |
| optimistical | 18 | - | - |
| optoacoustic | 18 | - | - |
| optometrical | 18 | - | - |
| optometrists | 16 | - | - |
| oracularness | 14 | - | - |
| oratorically | 17 | - | - |
| orbicularity | 19 | - | - |
| orchardgrass | 19 | - | - |
| orchestrally | 20 | - | - |
| orchestrater | 17 | - | - |
| orchestrates | 17 | - | - |
| orchestrinas | 17 | - | - |
| orchestrions | 17 | - | - |
| orchidaceous | 20 | - | - |
| orchidectomy | 25 | surgical removal of one or both testicles | - |
| orchidomania | 20 | - | - |
| orecchiettes | 19 | - | - |
| oreographies | 18 | - | - |
| orepearching | 20 | - | - |
| organicistic | 17 | relating to or tending toward organicism | - |
| organicities | 15 | - | - |
| organismally | 18 | - | - |
| organistrums | 15 | - | - |
| organogenies | 14 | - | - |
| organography | 22 | - | - |
| organoleptic | 17 | - | - |
| organologies | 14 | - | - |
| organologist | 14 | - | - |
| orgasmically | 20 | - | - |
| orgastically | 18 | - | - |
| orichalceous | 19 | - | - |
| orientalised | 13 | - | - |
| orientalises | 12 | - | - |
| orientalisms | 14 | - | - |
| orientalists | 12 | - | - |
| orientalized | 22 | - | - |
| orientalizes | 21 | - | - |
| orientations | 12 | - | - |
| originalisms | 15 | - | - |
| originalists | 13 | - | - |
| originations | 13 | - | - |
| orismologies | 15 | - | - |
| ornamentally | 17 | in an ornamental, nonfunctional manner | - |
| ornamentists | 14 | - | - |
| ornatenesses | 12 | - | - |
| ornerinesses | 12 | - | - |
| ornithogalum | 18 | sometimes placed in family Hyacinthaceae | - |
| ornithologic | 18 | - | - |
| ornithomancy | 22 | - | - |
| ornithomorph | 22 | - | - |
| ornithophily | 23 | - | - |
| ornithopters | 17 | - | - |
| ornithosaurs | 15 | - | - |
| ornithoscopy | 22 | - | - |
| orogenically | 18 | - | - |
| orographical | 20 | - | - |
| orologically | 18 | - | - |
| oromaxillary | 24 | - | - |
| oropharynges | 21 | - | - |
| oropharynxes | 27 | - | - |
| ororotundity | 16 | - | - |
| orotundities | 13 | - | - |
| orthoborates | 17 | - | - |
| orthocenters | 17 | - | - |
| orthocentres | 17 | - | - |
| orthocephaly | 25 | - | - |
| orthoclastic | 19 | - | - |
| orthocousins | 17 | - | - |
| orthodontias | 16 | - | - |
| orthodromics | 20 | - | - |
| orthodromies | 18 | - | - |
| orthogeneses | 16 | - | - |
| orthogenesis | 16 | - | - |
| orthogenetic | 18 | - | - |
| orthognathic | 21 | - | - |
| orthogonally | 19 | - | - |
| orthographer | 21 | - | - |
| orthographic | 23 | of or relating to or expressed in orthography | - |
| orthomorphic | 24 | - | - |
| orthopaedies | 18 | - | - |
| orthopaedist | 18 | a specialist in correcting deformities of the skeletal system (especially in children) | - |
| orthopedical | 20 | of or relating to orthopedics | - |
| orthopedists | 18 | - | - |
| orthopraxies | 24 | - | - |
| orthopterans | 17 | - | - |
| orthopterist | 17 | - | - |
| orthopteroid | 18 | - | - |
| orthopterous | 17 | - | - |
| orthorhombic | 24 | - | - |
| orthosilicic | 19 | - | - |
| orthotoneses | 15 | - | - |
| orthotonesis | 15 | - | - |
| orthotropies | 17 | - | - |
| orthotropism | 19 | - | - |
| orthotropous | 17 | (of a plant ovule) completely straight with the micropyle at the apex | - |
| orthovanadic | 21 | - | - |
| oryctologies | 18 | - | - |
| oscillations | 14 | - | - |
| oscillograms | 17 | - | - |
| oscillograph | 20 | a device for making a record of the wave forms of fluctuating voltages or currents | - |
| osculatories | 14 | - | - |
| osmolalities | 14 | - | - |
| osmolarities | 14 | - | - |
| osteichthyan | 23 | - | - |
| ostentations | 12 | - | - |
| osteoblastic | 16 | - | - |
| osteoclastic | 16 | - | - |
| osteodermous | 15 | - | - |
| osteogeneses | 13 | - | - |
| osteogenetic | 15 | - | - |
| osteological | 15 | - | - |
| osteologists | 13 | - | - |
| osteomalacia | 16 | abnormal softening of bones caused by deficiencies of phosphorus or calcium or vitamin D | - |
| osteomalacic | 18 | - | - |
| osteopathies | 17 | - | - |
| osteopathist | 17 | a therapist who manipulates the skeleton and muscles | - |
| osteoplastic | 16 | - | - |
| osteoporoses | 14 | - | - |
| osteoporotic | 16 | - | - |
| ostracisable | 16 | - | - |
| ostracizable | 25 | - | - |
| ostracoderms | 17 | - | - |
| ostreophages | 18 | - | - |
| otiosenesses | 12 | - | - |
| otoscleroses | 14 | - | - |
| otosclerosis | 14 | hereditary disorder in which ossification of the labyrinth of the inner ear causes tinnitus and eventual deafness | - |
| outachieving | 21 | - | - |
| outbalancing | 17 | - | - |
| outbargained | 16 | - | - |
| outblustered | 15 | - | - |
| outbrazening | 24 | - | - |
| outbreathing | 18 | - | - |
| outbreedings | 16 | - | - |
| outbuildings | 16 | - | - |
| outcavilling | 18 | - | - |
| outcompeting | 19 | - | - |
| outcraftying | 21 | - | - |
| outcroppings | 19 | - | - |
| outcrossings | 15 | - | - |
| outdatedness | 14 | - | - |
| outdelivered | 17 | - | - |
| outdesigning | 15 | - | - |
| outdistanced | 16 | - | - |
| outdistances | 15 | - | - |
| outdoorsiest | 13 | - | - |
| outercourses | 14 | - | - |
| outfangthief | 22 | - | - |
| outfightings | 20 | - | - |
| outgalloping | 16 | - | - |
| outgeneraled | 14 | - | - |
| outglittered | 14 | - | - |
| outgoingness | 14 | - | - |
| outhumouring | 18 | - | - |
| outintrigued | 14 | - | - |
| outintrigues | 13 | - | - |
| outjockeying | 29 | - | - |
| outlandishly | 19 | in an outlandish manner | the Bavarian was outlandishly dressed in lederhosen |
| outlaunching | 18 | - | - |
| outlustering | 13 | - | - |
| outmaneuvers | 17 | - | - |
| outmanoeuvre | 17 | defeat by more skillful maneuvering | - |
| outmarriages | 15 | - | - |
| outmastering | 15 | - | - |
| outmeasuring | 15 | - | - |
| outmodedness | 16 | - | - |
| outnumbering | 17 | - | - |
| outorganised | 14 | - | - |
| outorganises | 13 | - | - |
| outorganized | 23 | - | - |
| outorganizes | 22 | - | - |
| outpassioned | 15 | - | - |
| outperformed | 20 | - | - |
| outpoliticks | 20 | - | - |
| outpopulated | 17 | - | - |
| outpopulates | 16 | - | - |
| outpreaching | 20 | - | - |
| outproducing | 18 | - | - |
| outpromising | 17 | - | - |
| outreasoning | 13 | - | - |
| outrebounded | 16 | - | - |
| outreckoning | 19 | - | - |
| outreddening | 15 | - | - |
| outreproduce | 17 | - | - |
| outrivalling | 16 | - | - |
| outsavouring | 16 | - | - |
| outscreaming | 17 | - | - |
| outsiderness | 13 | - | - |
| outsourcings | 15 | - | - |
| outsparkling | 19 | - | - |
| outspreading | 16 | - | - |
| outspringing | 16 | - | - |
| outsprinting | 15 | - | - |
| outstraining | 13 | - | - |
| outstretches | 17 | - | - |
| outstripping | 17 | - | - |
| outsweetened | 16 | - | - |
| outthrobbing | 20 | - | - |
| outthrusting | 16 | - | - |
| outtraveling | 16 | - | - |
| outtravelled | 16 | - | - |
| outvillained | 16 | - | - |
| outwrestling | 16 | - | - |
| ovariotomies | 17 | - | - |
| ovariotomist | 17 | - | - |
| overabounded | 19 | - | - |
| overabstract | 19 | - | - |
| overabundant | 18 | excessively abundant | - |
| overachieved | 24 | - | - |
| overachieves | 23 | - | - |
| overactivity | 23 | excessive activity | overactivity of the sebaceous glands causes the skin to become oily |
| overadjusted | 24 | - | - |
| overanalysed | 19 | - | - |
| overanalyses | 18 | - | - |
| overanalysis | 18 | - | - |
| overanalyzed | 28 | - | - |
| overanalyzes | 27 | - | - |
| overarousals | 15 | - | - |
| overarranged | 17 | - | - |
| overarranges | 16 | - | - |
| overasserted | 16 | - | - |
| overassessed | 16 | - | - |
| overassesses | 15 | - | - |
| overbalanced | 20 | - | - |
| overbalances | 19 | - | - |
| overbettings | 18 | - | - |
| overbiddings | 20 | - | - |
| overblankets | 21 | - | - |
| overbleached | 23 | - | - |
| overbleaches | 22 | - | - |
| overblowings | 21 | - | - |
| overbookings | 22 | - | - |
| overborrowed | 21 | - | - |
| overbounding | 19 | - | - |
| overbreathed | 21 | - | - |
| overbreathes | 20 | - | - |
| overbreeding | 19 | - | - |
| overbridging | 20 | - | - |
| overbriefing | 21 | - | - |
| overbrimming | 22 | - | - |
| overbrowsing | 21 | - | - |
| overbuilding | 19 | - | - |
| overburthens | 20 | - | - |
| overcanopied | 20 | - | - |
| overcanopies | 19 | - | - |
| overcapacity | 24 | - | - |
| overcarrying | 21 | - | - |
| overcastings | 18 | - | - |
| overcatching | 23 | - | - |
| overcautions | 17 | - | - |
| overcharging | 22 | - | - |
| overchilling | 21 | - | - |
