ostracise

from WordNet (r) 3.0 (2006)

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

from The Collaborative International Dictionary of English v.0.48

ostracise \os"tra*cise\, v. t.
   Same as {ostracize}. [Chiefly Brit.]
   [PJC]