ethnarch /ˈɛθˌnɑːɹk/ noun2 •A leader of an ethnic community, especially a Jewish or (in the Ottoman Empire) Eastern Orthodox leader having political as well as spiritual authority.In fact, from a worldly perspective, sages were petty clerks, employees of the ethnarch of their ethnic group. The ethnarch may have treated sages with […] — 1984 •(historical) The governor of a Jewish province under the Roman Empire.In the course of the struggle with the unfortunate ethnarch, the nobles had found it expedient to attach themselves to Rome. — 1880 formsethnarchs