/ Dictionary / Index T threonine: Meaning and Definition of Find definitions for: thre•o•nine Pronunciation: (thrē'u-nēn", -nin), [key] — n. Biochem. an essential amino acid, CHCHOHCH(NH)COOH, obtained by the hydrolysis of proteins. Abbr.: Thr; Symbol: T Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: threonine (Thesaurus) threnody thresh Related Content Daily Word Quiz: profiterole Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language