11 Letter Countable Nouns Starting with O

Browse 126 valid English 11 letter countable nouns that start with O, from Opportunity, Observation, Orientation, Originality, Obstruction, Observatory and Opportunist to rarer terms. Check definitions and spelling below, or visit our noun grammar guide to review singular and plural count rules.

Refine list...
JUMP:
Sort:
Group:
Case:
View:
JUMP TO:
Select any word to view available definitions & photosSelect any word for details
Starts with OB18 words
observation
obstruction
observatory
obfuscation
obscuration
objectivist
obsessional
obscurement
obliterator
obstipation
objurgation
obtestation
obliquation
obsecration
obumbration
obsignation
obstriction
objurgatrix
Starts with OC8 words
occultation
octahedrite
octapeptide
octuplicate
octillionth
ochlophobic
octastichon
octingenary
Starts with OD3 words
odontoblast
odontophore
odontograph
Starts with OE
1 words
oenophilist
Starts with OF3 words
officiality
officiation
offscouring
Starts with OL3 words
oligopolist
oligochaete
oligochrome
Starts with OM
2 words
omphalocele
ommatophore
Starts with ON
2 words
onomasticon
oneirodynia
Starts with OO
1 words
oom-pah-pah
Starts with OP13 words
opportunity
opportunist
optometrist
optionality
opinionator
optocoupler
opisthosoma
operativity
ophthalmist
ophiologist
ophicalcite
ophidiarium
opeidoscope
Starts with OR24 words
orientation
originality
origination
orthography
orientalism
originalist
orientalist
orthopedist
ornithopter
orecchiette
orchiectomy
orbicularis
orthocenter
orthopteran
orchestrion
orientality
oracularity
organistrum
orchestrina
ornamentist
orthocousin
orthopteron
orthostichy
orthonectid
Starts with OS10 words
oscillation
ostentation
osteoplasty
osteologist
ostracoderm
oscillogram
ostensorium
osteography
osteoclasis
ostreophage
Starts with OU7 words
outbuilding
outcropping
outdoorsman
outpainting
outcrossing
outmarriage
outdwelling
Starts with OV24 words
overpayment
overthinker
overbooking
overbalance
overstretch
overharvest
overreacher
overvoltage
overspender
overnighter
oviposition
overclocker
overgarment
ovariectomy
overarousal
overconcern
overanxiety
overcoating
overblanket
overthrower
overdrinker
overleather
overmanager
overmeasure
Starts with OX
1 words
oxidization
Starts with OZ
2 words
ozonization
ozonosphere

•Browse Countable Nouns by Letter (A to Z)

Select a starting letter to browse countable nouns
ABCDEFGHIJKLMNOPQRSTUVWXYZ
Built for writers, students, and competitive word game players, Wordmom combines an uncluttered English dictionary and thesaurus with fast, pattern-based word finders so you can verify definitions, synonyms, and high-scoring tile plays in one place.
Word Games & Solvers
Word FinderScrabble Word FinderWords With Friends CheatWordle SolverAnagram Solver
Dictionary & Reference
DictionarySynonymsAntonymsWordsVocabulary HubPositive WordsNegative Words
Community
Contact UsEditorial PolicyPrivacy PolicyTerms and Conditions
© 2016–2026 Wordmom Network. All rights reserved. Made with for word lovers everywhere.
Disclaimer: SCRABBLE® is a registered trademark. All intellectual property rights in and to the game are owned in the U.S.A. and Canada by Hasbro Inc., and throughout the rest of the world by J.W. Spear & Sons Limited of Maidenhead, Berkshire, England, a subsidiary of Mattel Inc. Mattel and Spear are not affiliated with Hasbro. Words With Friends® is a registered trademark of Zynga Inc. Wordle® is a registered trademark of The New York Times Company. Other referenced game titles and tournament lexicon codes (including NASPA NWL and WESPA/HarperCollins CSW) are trademarks of their respective owners. Wordmom is an independent reference utility for educational and entertainment purposes and is not affiliated with, sponsored by, or endorsed by Hasbro, Mattel, Spear, Zynga, The New York Times Company, NASPA, WESPA, or HarperCollins Publishers. All game names are referenced strictly under nominative fair use to indicate compatibility.