Breadcrumb Home > Dictionary > Index B biotin: Meaning and Definition of Find definitions for: bi•o•tin Pronunciation: (bī'u-tin), [key] — n. Biochem. a crystalline, water-soluble vitamin, CHONS, of the vitamin B complex, that is present in all living cells and functions as a growth factor and as a catalyst in carboxylation reactions. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: biotin (Thesaurus) biotic potential biotite ✖ Related Content Daily Word Quiz: cacophony Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language