Final answer:
Excommunication is a punishment handed out by a church when one of its members breaks an important church rule. The person is placed outside the church, its communion, and the sacraments. This punishment was often used by the Catholic Church during the Middle Ages to reform offenders.
Step-by-step explanation:
A punishment that is handed out by a church when one of its members breaks some important church rule is called excommunication. Excommunication is a form of punishment where the person is placed outside the church, its communion, and the sacraments. This punishment was often used by the Catholic Church during the Middle Ages to reform offenders and maintain the authority of the church.