The Collaborative International Dictionary of English v.0.48:

Oxy- \Ox"y-\ (Chem.)
   A prefix, also used adjectively, designating:
   (a) A compound containing oxygen.
   (b) A compound containing the hydroxyl group, more properly
       designated by hydroxy-. See Hydroxy-.
       [1913 Webster]

   Oxy acid. See Oxyacid (below).
      [1913 Webster]