Countable Nouns That Start with O and End with OS

Explore 8 verified English countable nouns starting with O and ending with OS, including Ouroboros, Omphalos, Opisthotonos, Orthros, Onos, Opisthodomos and Os. Sort these count nouns with singular and plural forms by word length for ESL grammar practice, determiner usage, and plural spelling below, or review singular and plural count rules in our noun grammar guide.

Refine list...
JUMP:
Sort:
Group:
Case:
View:
JUMP TO:
Select any word to view available definitions & photosSelect any word for details
Starts with OM
1 words
omphalos
Starts with ON
1 words
onos
Starts with OP
2 words
opisthotonos
opisthodomos
Starts with OR
1 words
orthros
Starts with OS
1 words
os
Starts with OU
1 words
ouroboros
Starts with OV
1 words
ovibos

•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.