/ Dictionary / Index S synostosis: Meaning and Definition of Find definitions for: syn•os•to•sis Pronunciation: (sin"o-stō'sis), [key] — pl. -ses union of separate bones into a single bone. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. synosteosis synovia Related Content Daily Word Quiz: fidelity Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language