/ Dictionary / Index S sarcosome: Meaning and Definition of Find definitions for: sar•co•some Pronunciation: (sär'ku-sōm"), [key] — n. Cell Biol. a mitochondrion occurring in a muscle fiber. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: sarcosome (Thesaurus) sarcosine sarcous Related Content Daily Word Quiz: lyceum Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language