Sentence:  Children <WSD>ostracize</WSD> other children in the playground, choosing carefully who they wish to play with. Adults <WSD>ostracize</WSD> other adults, such as marriage partners using the silent treatment. 
Meaning of the word marked with <WSD> tags:  To exclude (a person) from society or from a community, by not communicating with (them) or by refusing to acknowledge (their) presence; to refuse to talk to or associate with; to shun.