C3H4OHCO2H3

Citric Cit"ric, a. [Cf. F. citrique. See {Citron}.] (Chem.) Of, pertaining to, or derived from, the citron or lemon; as, citric acid. [1913 Webster]

{Citric acid} (Chem.), an organic acid, {C3H4OH.(CO2H)3}, extracted from lemons, currants, gooseberries, etc., as a white crystalline substance, having a pleasant sour taste. [1913 Webster]