from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A colorless crystalline compound, C7H6O5, derived from tannin and used as a tanning agent, as an ink dye, and in photography and the manufacture of paper.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. a phenolic carboxylic acid, 3,4,5-trihydroxybenzoic acid, found in galls, tea, the bark of some trees etc; a constituent of tannin
- n. the supposed acid H3GaO3, the acid form of the amphoteric gallium hydroxide Ga(OH)3, known only as alkali metal salts
from the GNU version of the Collaborative International Dictionary of English
- adj. an organic acid, very widely distributed in the vegetable kingdom, being found in the free state in galls, tea, etc., and produced artificially. It is a white, crystalline substance, C6H2(HO)3.CO2H, with an astringent taste, and is a strong reducing agent, as employed in photography. It is usually prepared from tannin, and both give a dark color with iron salts, forming tannate and gallate of iron, which are the essential ingredients of common black ink.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a colorless crystalline acid obtained from tannin
French acide gallique, from galle, plant gall; see gall3.(American Heritage® Dictionary of the English Language, Fourth Edition)