Wiktionary
gentisic acid
n. (context organic compound English) A dihydroxybenzoic acid produced by carboxylation of hydroquinone.
Wikipedia
Gentisic acid
Gentisic acid is a dihydroxybenzoic acid. It is a derivative of benzoic acid and a minor (1%) product of the metabolic break down of aspirin, excreted by the kidneys.
It is also found in the African tree Alchornea cordifolia and in wine.