The Collaborative International Dictionary of English v.0.48:

Glycolic \Gly*col"ic\, a. (Chem.)
   Pertaining to, or derived from, glycol; as, glycolic ether;
   glycolic acid.
   [1913 Webster]

   Glycolic acid (Chem.), an organic acid, found naturally in
      unripe grapes and in the leaves of the wild grape
      (Ampelopsis quinquefolia), and produced artificially in
      many ways, as by the oxidation of glycol, -- whence its
      name. It is a sirupy, or white crystalline, substance,
      HO.CH2.CO2H, has the properties both of an alcohol and
      an acid, and is a type of the hydroxy acids; -- called
      also hydroxyacetic acid.
      [1913 Webster]

WordNet (r) 3.0 (2006):

glycolic acid
    n 1: a translucent crystalline compound found in sugar cane and
         sugar beets and unripe grapes [syn: glycolic acid,
         glycollic acid, hydroxyacetic acid]