to send someone away, especially from their country, and not allow them to come back

He was banished to an uninhabited island for a year. 他被流放到一个荒无人迹的小岛上呆了一年。

They were banished (= sent out) from the library for making a noise. 他们因为大声喧哗被赶出了图书馆。

to get rid of something completely

Try to banish all thoughts of revenge from your mind. 你必须努力打消所有复仇的念头。