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]

WordNet (r) 3.0 (2006):

oxidize
    v 1: enter into a combination with oxygen or become converted
         into an oxide; "This metal oxidizes easily" [syn:
         oxidise, oxidize, oxidate]
    2: add oxygen to or combine with oxygen [syn: oxidize,
       oxidise, oxidate] [ant: deoxidise, deoxidize,
       reduce]

Moby Thesaurus II by Grady Ward, 1.0:

62 Moby Thesaurus words for "oxidize":
   acetify, acidify, acidulate, alkalify, alkalize, blaze, blister,
   borate, brand, burn, burn in, burn off, canker, carbonate, cast,
   catalyze, cauterize, char, chemical, chlorinate, coal, corrode,
   crack, cupel, eat, eat away, eat into, electrolyze, erode, ferment,
   flame, found, gnaw, homopolymerize, hydrate, hydrogenate,
   hydroxylate, isomerize, nibble away, nitrate, oxidate, parch,
   pepsinate, peroxidize, phosphatize, polymerize, pyrolyze, reduce,
   rust, scorch, sear, singe, solder, sulfate, sulfatize, sulfonate,
   swinge, torrefy, vesicate, vulcanize, weld, work