A province, prefecture, or territory, under the jurisdiction of an eparch or governor; esp., in modern Greece, one of the larger subdivisions of a monarchy or province of the kingdom; in Russia, a diocese or archdiocese.
Eparchy is an anglicized Greek word, authentically latinized as eparchia and loosely translating as 'rule over something', but has the following specific meanings, both in political history and in the hierarchy of eastern churches.