'Hydroxy acid' definitions:

Definition of 'hydroxy acid'

(from WordNet)
noun
Any acid that has hydroxyl groups in addition to the hydroxyl group in the acid itself

Definition of 'Hydroxy acid'

From: GCIDE
  • Hydroxy- \Hy*drox"y-\ (Chem.) A combining form, also used adjectively, indicating hydroxyl as an ingredient. [1913 Webster]
  • Hydroxy acid (Chem.), an organic acid, having (besides the hydroxyl group of the carboxyl radical) an alcoholic hydroxyl group, and thus having the qualities of an alcohol in addition to its acid properties; as, lactic and tartaric acids are hydroxy acids. [1913 Webster]