Source : Webster's Revised Unabridged Dictionary (1913)

Ostracize \Os"tra*cize\, v. t. [imp. & p. p. {Ostracized}; p.
   pr. & vb. n. {Ostracizing}.] [Gr. ?, fr. ? a tile, a tablet
   used in voting, a shell; cf. ? oyster, ? bone. Cf. {Osseous},
   {Oyster}.]
   1. (Gr. Antiq.) To exile by ostracism; to banish by a popular
      vote, as at Athens. --Grote.

   2. To banish from society; to put under the ban; to cast out
      from social, political, or private favor; as, he was
      ostracized by his former friends. --Marvell.

Source : WordNet®

ostracize
     v 1: expel from a community or group [syn: {banish}, {ban}, {ostracise},
           {shun}, {cast out}, {blackball}]
     2: avoid speaking to or dealing with; "Ever since I spoke up,
        my colleagues ostracize me" [syn: {ostracise}]