/ Dictionary / Index A arginine: Meaning and Definition of Find definitions for: ar•gi•nine Pronunciation: (är'ju-nēn", -nīn", -nin), [key] — n. Biochem. an essential amino acid, CHNO: the free amino acid increases insulin secretion and is converted to urea in the liver by arginase. Abbr.: Arg; Symbol: R Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: arginine (Thesaurus) arginase Argive Related Content Daily Word Quiz: resilient Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language