/ Dictionary / Index C coss: Meaning and Definition of Find definitions for: coss Pronunciation: (kōs), [key] — n. kos. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: coss (Thesaurus) cosponsor Cossack Related Content Daily Word Quiz: wary Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language