/ Thesaurus / N Synonyms of nicotinic acid Find synonyms for: Noun1. niacin, nicotinic acid, B-complex vitamin, B complex, vitamin B complex, vitamin B, B vitamin, Busage: a B vitamin essential for the normal function of the nervous system and the gastrointestinal tractWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: reticent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language