from The American Heritage® Dictionary of the English Language, 4th Edition
- n. See niacin.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. pyridine-3-carboxylic acid; together with nicotinamide is a part of the vitamin B complex.
from the GNU version of the Collaborative International Dictionary of English
- n. An organic acid (C6H5NO2), a carboxylated derivative of pyridine, obtained by the oxidation of nicotine; called also niacin and antipellagra vitamin, and vitamin B5. Chemically it is 3-pyridinecarboxylic acid.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a B vitamin essential for the normal function of the nervous system and the gastrointestinal tract
So called because it is often obtained by oxidizing nicotine.(American Heritage® Dictionary of the English Language, Fourth Edition)