/ Dictionary / Index C cystathionine: Meaning and Definition of Find definitions for: cys•ta•thi•o•nine Pronunciation: (sis"tu-thī'u-nēn", -nin), [key] — n. Biochem. an amino acid, CHONS, that is an intermediate in the transfer of sulfur from methionine to cysteine. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. cyst cystectomy Related Content Daily Word Quiz: abstain Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language