from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A substance, such as a vitamin or mineral, that is essential in minute amounts for the proper growth and metabolism of a living organism.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A mineral, vitamin or other substance that is essential, even in very small quantities, for growth or metabolism
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a substance needed only in small amounts for normal body function (e.g., vitamins or minerals)
Sorry, no etymologies found.