To excommunicate someone means to officially exclude them from participating in the religious community of a church. This action is often taken when a member is believed to have committed serious offenses against the beliefs or rules of the church. The person who is excommunicated is typically barred from receiving sacraments and may be shunned by other members. Excommunication is a practice found in various religious traditions, including Christianity, particularly within the Catholic Church. It serves as a form of discipline intended to encourage repentance and reconciliation, allowing the individual to return to the community if they seek forgiveness and change their behavior.