Pronunciation: (me-thī'u-nēn", -nin), [key]
an amino acid, CH3SCH2CH2CH(NH2)COOH, found in casein, wool, and other proteins or prepared synthetically: used as a supplement to a special diet in the prevention and treatment of certain liver diseases. Abbr.: Met; Symbol: M
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.