A synod is a council of the Christian church. The word comes from the Greek synodos meaning an assembly and is synonymous with the word council that comes from the Latin concilium. The Slavic term sobor has the same meaning, although it also can apply to a church building, generally major churches and cathedrals.
In Orthodox practice either word applies to a meeting of a body of the Church to decide issues of doctrine or of administration of the body, both at local as well as higher levels of the churches. An ecumenical council is a synod of the whole church. The word synod is frequently applied in the Orthodox church to the standing councils of high ranking bishops of autonomous and autocephalous churches that oversee the day-to-day administration of the church, usually referred to as holy synods.
- Catholic Encyclopedia