The act of banishing a member of a church from the communion of believers and the privileges of the church; cutting a person off from a religious society WordNet 3.0 & Open English WordNet

Excommunication is an institutional act of religious censure used to deprive, suspend, or limit membership in a religious community or to restrict certain rights within it, in particular those of being in communion with other members of the congregation, and of receiving the sacraments. Wikipedia

Censure used to deprive, suspend, or limit membership in a religious community Wikidata

The ecclesiastical sentence by which a person is excommunicated. OmegaWiki

The act of excommunicating, disfellowshipping or ejecting; especially an ecclesiastical censure whereby the person against whom it is pronounced is, for the time, cast out of the communication of the church; exclusion from fellowship in things spiritual. Wiktionary

Act of excommunicating, disfellowshipping or ejecting. Wiktionary (translation)