The American Heritage® Dictionary of the English Language, 4th Edition
n. A physiologically active amine, C5H9N3, found in plant and animal tissue and released from mast cells as part of an allergic reaction in humans. It stimulates gastric secretion and causes dilation of capillaries, constriction of bronchial smooth muscle, and decreased blood pressure.
n. An amine, C5H9N3, formed by decarboxylation of histidine, that causes dilatation of capillaries, contraction of smooth muscle, and stimulation of gastric acid secretion; it is released during allergic reactions.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. amine formed from histidine that stimulates gastric secretions and dilates blood vessels; released by the human immune system during allergic reactions
Word Usage
"Beer, wine and liquor contain histamine, produced by yeast and bacteria during the fermentation process."