Source : Webster's Revised Unabridged Dictionary (1913)

Ostentation \Os`ten*ta"tion\, n. [L. ostentatio: cf. F.
   ostentation.]
   1. The act of ostentating or of making an ambitious display;
      unnecessary show; pretentious parade; -- usually in a
      detractive sense. ``Much ostentation vain of fleshly
      arm.'' --Milton.

            He knew that good and bountiful minds were sometimes
            inclined to ostentation.              --Atterbury.

   2. A show or spectacle. [Obs.] --Shak.

   Syn: Parade; pageantry; show; pomp; pompousness; vaunting;
        boasting. See {Parade}.

Source : WordNet®

ostentation
     n 1: a showy outward display [syn: {fanfare}]
     2: lack of elegance as a consequence of being pompous and
        puffed up with vanity [syn: {ostentatiousness}, {pomposity},
         {pompousness}, {pretentiousness}, {splashiness}, {inflation}]
     3: pretentious or showy or vulgar display