\Hy*drox"y-\ (Chem.)
A combining form, also used adjectively, indicating hydroxyl
as an ingredient.
{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.