The Collaborative International Dictionary of English v.0.48:

Oxygenate \Ox"y*gen*ate\, v. t. [imp. & p. p. Oxygenated; p.
   pr. & vb. n. Oxygenating.] [Cf. F. oxyg['e]ner.] (Chem.)
   To unite, or cause to combine, with oxygen; to treat with
   oxygen; to oxidize; as, oxygenated water (hydrogen dioxide).
   [1913 Webster]

WordNet (r) 3.0 (2006):

oxygenate
    v 1: impregnate, combine, or supply with oxygen; "oxygenate
         blood" [syn: oxygenate, oxygenize, oxygenise,
         aerate]

Moby Thesaurus II by Grady Ward, 1.0:

41 Moby Thesaurus words for "oxygenate":
   aerate, aerify, air, air out, air-condition, air-cool, airify,
   atomize, carbonate, chlorinate, cross-ventilate, distill, emit,
   etherify, etherize, evaporate, exhale, fan, fluidize, fractionate,
   freshen, fume, fumigate, gasify, give off, hydrogenate, oxygenize,
   perfume, reek, refresh, send out, smoke, spray, steam, sublimate,
   sublime, vaporize, ventilate, volatilize, wind, winnow