Excommunication is the exclusion of an Orthodox Christian from the Eucharist, that is from Communion. It is a form of church discipline. The act of excommunication is considered a transient action concerning a member who has done something that separates him from the church community as attempts are made of restoring the member to full communion.
The word excommunication is from the Latin, ex meaning out of, and communio or communicatio meaning communion, thus ‘exclusion from the communion’.
For serious acts, such as unrepentant heresy, the church pronounces an anathema as a means of expulsion that leaves the person outside of the Church and to his own devices.