/ Dictionary / Index C cycasin: Meaning and Definition of Find definitions for: cy•ca•sin Pronunciation: (sī'ku-sin), [key] — n. a naturally occurring toxic glucoside, CHNO, obtained from the seeds of cycad plants, carcinogenic in humans and other mammals. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. cycas cycl- Related Content Daily Word Quiz: agitated Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language