Source : Webster's Revised Unabridged Dictionary (1913)

Patronize \Pa"tron*ize\, v. t. [imp. & p. p. {Patronized}; p.
   pr. & vb. n. {Patronizing}.]
   1. To act as patron toward; to support; to countenance; to
      favor; to aid.

            The idea has been patronized by two States only.
                                                  --A. Hamilton.

   2. To trade with customarily; to frequent as a customer.
      [Commercial Cant]

   3. To assume the air of a patron, or of a superior and
      protector, toward; -- used in an unfavorable sense; as, to
      patronize one's equals.

Patronizing \Pa"tron*i`zing\, a.
   Showing condescending favor; assuming the manner of airs of a
   superior toward another. -- {Pat"ron*i`zing*ly}, adv.
   Thackeray.

Source : WordNet®

patronizing
     adj : (used of behavior or attitude) characteristic of those who
           treat others with condescension [syn: {arch}, {condescending},
            {patronising}]