The Collaborative International Dictionary of English v.0.48:

Oxidize \Ox"i*dize\ ([o^]ks"[i^]*d[imac]z), v. t. [imp. & p. p.
   Oxidized ([o^]ks"[i^]*d[imac]zd); p. pr. & vb. n.
   Oxidizing.] (Chem.)
   To combine with oxygen, or subject to the action of oxygen,
   or of an oxidizing agent. Specifically:
   (a) To combine with oxygen or with more oxygen; to add oxygen
       to; as, to oxidize nitrous acid so as to form nitric
       acid.
   (b) To remove hydrogen from (anything), as by the action of
       oxygen; as, to oxidize alcohol so as to form aldehyde.
   (c) To subject to the action of oxygen or of an oxidizing
       agent, so as to bring to a higher grade, as an -ous
       compound to an -ic compound; as, to oxidize mercurous
       chloride to mercuric chloride.
       [1913 Webster]

   Note: In certain cases to oxidize is identical with to
         acidify; for, in nearly all cases, the more oxygen a
         substance contains the more nearly does it approximate
         to acid qualities; thus, by oxidation many elements, as
         sulphur, nitrogen, carbon, chromium, manganese, etc.,
         pass into compounds which are acid anhydrides, and thus
         practically in the acid state.
         [1913 Webster]