What is "send to coventry"

vb. (context transitive idiomatic English) To ostracize, or systematically ignore someone.

To send someone to Coventry is an English idiom meaning to deliberately ostracise someone. Typically, this is done by not talking to them, avoiding someone's company, and generally pretending that they no longer exist. Victims are treated as though they are completely invisible and inaudible. The Coventry referred to in the phrase is a cathedral city in Warwickshire.