noun 1.Eastern Church.b.a title originally applied to a patriarch but later applied only to a bishop ranking below a patriarch and above a metropolitan.
2.the ruler of a province in the Byzantine Empire.
Origin: 1580–90; <
Late Latin exarchus superintendent <
Greek éxarchos overseer, leader, equivalent to
ex- ex-3 +
-archos -arch Related forms ex·arch·al, adjective