ecumenical studies

a movement among Protestant groups since the 1800s aimed at achieving universal Christian unity through international or interdenominational organizations. There are also Ecumenical Councils in the Roman Catholic church; since the Great Schism (1054), the Eastern churches have not been involved.

plural of Ecumenical Patriarch

The Orthodox archbishop of Constantinople who is generally recognised as the leader of the Eastern Orthodox Church

plural of ecumenical council

(Christianity) A church council to which bishops from the entire world are invited, held by Roman Catholic and Eastern Orthodox Christians to be infallible in its decisions on faith and morals when certain conditions are met.