A synod is a council of the Christian church. The word comes from the Greek σύνοδος; 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.