15-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 |
|---|---|---|---|
| ophthalmologist | 26 | a medical doctor specializing in the diagnosis and treatment of diseases of the eye | - |
| oversimplifying | 29 | - | - |
| objectification | 31 | a concrete representation of an abstract idea or principle | - |
| overdramatizing | 31 | - | - |
| objectivenesses | 29 | - | - |
| obliviousnesses | 20 | - | - |
| obnoxiousnesses | 24 | - | - |
| observabilities | 22 | - | - |
| observationally | 23 | - | - |
| obsessivenesses | 20 | - | - |
| obstinatenesses | 17 | - | - |
| obstructionally | 22 | - | - |
| obstructionisms | 21 | - | - |
| obstructionists | 19 | - | - |
| obstructiveness | 22 | - | - |
| obtainabilities | 19 | - | - |
| obtrusivenesses | 20 | - | - |
| occasionalities | 19 | - | - |
| occidentalising | 21 | - | - |
| occidentalizing | 30 | - | - |
| occlusivenesses | 22 | - | - |
| oceanographical | 25 | - | - |
| ochlocratically | 27 | - | - |
| octocentenaries | 19 | - | - |
| odontorhynchous | 27 | - | - |
| odontostomatous | 18 | - | - |
| odoriferousness | 19 | - | - |
| oesophagoscopes | 25 | - | - |
| oestrogenically | 21 | - | - |
| offensivenesses | 24 | - | - |
| offhandednesses | 26 | - | - |
| officiousnesses | 23 | - | - |
| oligocythaemias | 26 | - | - |
| oligodendrocyte | 23 | a cell of the oligodendroglia | - |
| oligodendroglia | 19 | tissue consisting of glial cells with sheetlike processes that form the myelin sheath of nerve fibers | - |
| oligomerisation | 18 | - | - |
| oligomerization | 27 | - | - |
| oligonucleotide | 19 | (biochemistry) a polynucleotide whose molecules contain relatively few nucleotides | - |
| oligosaccharide | 24 | any of the carbohydrates that yield only a few monosaccharide molecules on complete hydrolysis | - |
| omnibenevolence | 24 | - | - |
| omnicompetences | 25 | - | - |
| omnidirectional | 20 | not directional | omnidirectional antenna |
| omnifariousness | 20 | - | - |
| omnisexualities | 24 | - | - |
| omoplatoscopies | 23 | - | - |
| oncogeneticists | 20 | - | - |
| oneirocriticism | 21 | - | - |
| ontogenetically | 21 | - | - |
| onychocryptoses | 30 | - | - |
| onychocryptosis | 30 | - | - |
| oophorectomised | 25 | - | - |
| oophorectomises | 24 | - | - |
| oophorectomized | 34 | - | - |
| oophorectomizes | 33 | - | - |
| openheartedness | 21 | - | - |
| openmouthedness | 23 | - | - |
| operationalisms | 19 | - | - |
| operationalists | 17 | - | - |
| operativenesses | 20 | - | - |
| ophthalmologies | 26 | - | - |
| ophthalmometers | 27 | - | - |
| ophthalmophobia | 32 | - | - |
| ophthalmoplegia | 28 | paralysis of the motor nerves of the eye | - |
| ophthalmoscopes | 29 | - | - |
| ophthalmoscopic | 31 | - | - |
| opinionatedness | 18 | - | - |
| opisthognathism | 26 | - | - |
| opisthognathous | 24 | having receding jaws | - |
| opisthographies | 26 | - | - |
| opportunenesses | 19 | - | - |
| opprobriousness | 21 | - | - |
| opsonifications | 22 | - | - |
| optimalisations | 19 | - | - |
| optimalizations | 28 | - | - |
| optoelectronics | 21 | - | - |
| oraculousnesses | 17 | - | - |
| orchesographies | 26 | - | - |
| orchestrational | 20 | - | - |
| oreographically | 26 | - | - |
| organochlorines | 21 | - | - |
| organographical | 24 | - | - |
| organographists | 22 | - | - |
| organomercurial | 20 | - | - |
| organometallics | 20 | - | - |
| organophosphate | 26 | an insecticide that interferes with an insect's nervous system | - |
| organotherapies | 21 | - | - |
| orientalization | 24 | - | - |
| orientationally | 18 | - | - |
| ornithodelphian | 24 | - | - |
| ornithodelphous | 24 | - | - |
| ornithorhynchus | 29 | type genus of the family Ornithorhynchidae | - |
| orthochromatism | 27 | - | - |
| orthodontically | 24 | - | - |
| orthogonalising | 20 | - | - |
| orthogonalities | 19 | - | - |
| orthogonalizing | 29 | - | - |
| orthopaedically | 26 | - | - |
| orthophosphates | 28 | - | - |
| orthophosphoric | 30 | - | - |
| orthopsychiatry | 31 | - | - |
| oscillographies | 23 | - | - |
| osmoregulations | 18 | - | - |
| ostensibilities | 17 | - | - |
| osteoarthritics | 20 | - | - |
| osteomyelitides | 21 | - | - |
| osteomyelitises | 20 | - | - |
| osteopathically | 25 | - | - |
| ostreiculturist | 17 | - | - |
| otherworldliest | 22 | - | - |
| outdoorsmanship | 23 | - | - |
| outmanipulating | 20 | - | - |
| outspokennesses | 21 | - | - |
| overabstracting | 23 | - | - |
| overabstraction | 22 | - | - |
| overaccentuated | 23 | - | - |
| overaccentuates | 22 | - | - |
| overachievement | 28 | better than expected performance (better than might have been predicted from intelligence tests) | - |
| overadjustments | 28 | - | - |
| overadvertising | 23 | - | - |
| overadvertizing | 32 | - | - |
| overalertnesses | 18 | - | - |
| overambitiously | 25 | - | - |
| overapplication | 24 | - | - |
| overarticulated | 21 | - | - |
| overarticulates | 20 | - | - |
| overassessments | 20 | - | - |
| overbearingness | 21 | the trait of being imperious and overbearing | - |
| overcapitalised | 23 | - | - |
| overcapitalises | 22 | - | - |
| overcapitalized | 32 | - | - |
| overcapitalizes | 31 | - | - |
| overcentralised | 21 | - | - |
| overcentralises | 20 | - | - |
| overcentralized | 30 | - | - |
| overcentralizes | 29 | - | - |
| overclassifying | 27 | - | - |
| overcommitments | 26 | - | - |
| overcommunicate | 26 | - | - |
| overcompensated | 25 | - | - |
| overcompensates | 24 | - | - |
| overcompliances | 26 | - | - |
| overcomplicated | 27 | - | - |
| overcomplicates | 26 | - | - |
| overcompressing | 25 | - | - |
| overconfidences | 26 | - | - |
| overconfidently | 27 | - | - |
| overconstructed | 23 | - | - |
| overconsumption | 24 | - | - |
| overcontrolling | 21 | - | - |
| overcorrections | 22 | - | - |
| overcredulities | 21 | - | - |
| overcultivation | 23 | - | - |
| overdecorations | 21 | - | - |
| overdependences | 24 | - | - |
| overdevelopment | 26 | - | - |
| overdiscounting | 22 | - | - |
| overdiversified | 26 | - | - |
| overdiversities | 22 | - | - |
| overdocumenting | 24 | - | - |
| overdramatising | 22 | - | - |
| overeagernesses | 19 | - | - |
| overearnestness | 18 | - | - |
| overelaborating | 21 | - | - |
| overelaboration | 20 | - | - |
| overembellished | 26 | - | - |
| overembellishes | 25 | - | - |
| overemotionally | 23 | - | - |
| overemphasising | 26 | - | - |
| overemphasizing | 35 | - | - |
| overemployments | 27 | - | - |
| overencouraging | 22 | - | - |
| overengineering | 20 | - | - |
| overentertained | 19 | - | - |
| overenthusiasms | 23 | - | - |
| overestimations | 20 | - | - |
| overevaluations | 21 | - | - |
| overexaggerated | 28 | - | - |
| overexaggerates | 27 | - | - |
| overexcitements | 29 | - | - |
| overexpectation | 29 | - | - |
| overextractions | 27 | - | - |
| overextrapolate | 27 | - | - |
| overextravagant | 29 | - | - |
| overexuberantly | 30 | - | - |
| overfamiliarity | 26 | - | - |
| overfertilising | 22 | - | - |
| overfertilizing | 31 | - | - |
| overflourishing | 25 | - | - |
| overforwardness | 25 | - | - |
| overfulfillment | 26 | - | - |
| overgeneralised | 20 | - | - |
| overgeneralises | 19 | - | - |
| overgeneralized | 29 | - | - |
| overgeneralizes | 28 | - | - |
| overglamorising | 22 | - | - |
| overglamorizing | 31 | - | - |
| overglamourized | 31 | - | - |
| overglamourizes | 30 | - | - |
| overhastinesses | 21 | - | - |
| overhomogenised | 25 | - | - |
| overhomogenises | 24 | - | - |
| overhomogenized | 34 | - | - |
| overhomogenizes | 33 | - | - |
| overidentifying | 26 | - | - |
| overimaginative | 24 | - | - |
| overindulgences | 22 | - | - |
| overingenuities | 19 | - | - |
| overintensities | 18 | - | - |
| overinterpreted | 21 | - | - |
| overinvestments | 23 | - | - |
| overlengthening | 23 | - | - |
| overmanagements | 23 | - | - |
| overmedications | 23 | - | - |
| overmultiplying | 26 | - | - |
| overmultituding | 22 | - | - |
| overnourishment | 23 | - | - |
| overopinionated | 21 | - | - |
| overorchestrate | 23 | - | - |
| overornamenting | 21 | - | - |
| overpersuasions | 20 | - | - |
| overpessimistic | 24 | - | - |
| overpopulations | 22 | - | - |
| overpredictions | 23 | - | - |
| overpreparation | 22 | - | - |
| overprescribing | 25 | - | - |
| overproductions | 23 | - | - |
| overprogramming | 26 | - | - |
| overproportions | 22 | - | - |
| overprotections | 22 | - | - |
| overrefinements | 23 | - | - |
| overregulations | 19 | - | - |
| overrepresented | 21 | - | - |
| oversaturations | 18 | - | - |
| oversensitivity | 24 | - | - |
| overspecialised | 23 | - | - |
| overspecialises | 22 | - | - |
| overspecialized | 32 | - | - |
| overspecializes | 31 | - | - |
| overspeculating | 23 | - | - |
| overspeculation | 22 | - | - |
| overstabilities | 20 | - | - |
| overstimulating | 21 | - | - |
| overstimulation | 20 | - | - |
| overstructuring | 21 | - | - |
| oversubscribing | 25 | - | - |
| oversweetnesses | 21 | - | - |
| overutilisation | 18 | exploitation to the point of diminishing returns | - |
| overutilization | 27 | exploitation to the point of diminishing returns | - |
| overweeningness | 22 | - | - |
| overwithholding | 29 | - | - |
| overzealousness | 27 | - | - |
| ovoviviparities | 26 | - | - |
| ovoviviparously | 29 | - | - |
| oxidoreductases | 26 | - | - |
| oxyhaemoglobins | 33 | - | - |
| oxyphenbutazone | 41 | an anti-inflammatory drug (trade name Tandearil) used to treat arthritis and bursitis | - |
| oxytetracycline | 32 | a yellow crystalline antibiotic (trademark Terramycin) obtained from a soil actinomycete; used to treat various bacterial and rickettsial infections | - |
