/ Dictionary / Index C Cossack: Meaning and Definition of Find definitions for: Cos•sack Pronunciation: (kos'ak, -uk), [key] — n. (esp. in czarist Russia) a person belonging to any of certain groups of Slavs living chiefly in the southern part of Russia in Europe and forming an elite corps of horsemen. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: cossack (Thesaurus) coss cosset Related Content Daily Word Quiz: reclusive Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language