/ Dictionary / Index N niacinamide: Meaning and Definition of Find definitions for: ni•a•cin•a•mide Pronunciation: (nī"u-sin'u-mīd"), [key] — n. Biochem. nicotinamide. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. niacin Niagara Related Content Daily Word Quiz: eureka Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language