/ Dictionary / Index B betaine: Meaning and Definition of Find definitions for: be•ta•ine Pronunciation: (bē'tu-ēn", -in&wdspcbi-tā'ēn, -in), [key] — n. Chem., Pharm. a colorless, crystalline, water-soluble, sweet-tasting alkaloid, CHNO, usually obtained from sugar beets or synthesized from glycine, used chiefly in medicine. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: betaine (Thesaurus) beta-indoleacetic acid beta iron Related Content Daily Word Quiz: aversion Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language