The Collaborative International Dictionary of English v.0.48:
ostracise \os"tra*cise\, v. t. Same as ostracize. [Chiefly Brit.] [PJC]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]