/ Dictionary / Index O ostosis: Meaning and Definition of Find definitions for: os•to•sis Pronunciation: (o-stō'sis), [key] — n. Physiol. the formation of bone; ossification. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. ostomy Ostpolitik Related Content Daily Word Quiz: acquiesce Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language