From WordNet (r) 3.0 (2006):
banish
v 1: expel from a community or group [syn: banish, ban,
ostracize, ostracise, shun, cast out, blackball]
2: ban from a place of residence, as for punishment [syn:
banish, ban]
3: expel, as if by official decree; "he was banished from his
own country" [syn: banish, relegate, bar]
4: drive away; "banish bad thoughts"; "banish gloom"