/ Dictionary / Index O ossa: Meaning and Definition of Find definitions for: os•sa Pronunciation: (os'u), [key] — n. pl. of Os•sa Pronunciation: (os'u), [key] — n. a mountain in E Greece, in Thessaly. 6490 ft. (1978 m). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: ossa (Thesaurus) OSS ossein Related Content Daily Word Quiz: abstain Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language