/ Dictionary / Index C cuprous cyanide: Meaning and Definition of Find definitions for: cu'prous cy'anide Pronunciation: [key] a creamy-white, highly poisonous, water-insoluble powder, CuCN, used chiefly in electroplating and in organic synthesis. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. cuprous cuprum Related Content Daily Word Quiz: cur Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language