Definitions for gallic acid
Random House Webster's College Dictionary
a white or yellowish solid, C7H6O5, obtained from nutgalls, used esp. in tanning and dyes.
Origin of gallic acid:
1785–95; < F
a colorless crystalline acid obtained from tannin
a phenolic carboxylic acid, 3,4,5-trihydroxybenzoic acid, found in galls, tea, the bark of some trees etc; a constituent of tannin
the supposed acid HGaO, the acid form of the amphoteric gallium hydroxide Ga(OH), known only as alkali metal salts
U.S. National Library of Medicine
A colorless or slightly yellow crystalline compound obtained from nutgalls. It is used in photography, pharmaceuticals, and as an analytical reagent.