exarch

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A bishop in the Eastern Orthodox Church ranking immediately below a patriarch.
2. n. The ruler of a province in the Byzantine Empire.
3. adj. Botany Of or relating to a xylem whose early development is away from the center and toward the periphery.

Century Dictionary and Cyclopedia

1. n. The ruler of a province in the Byzantine empire. The most important was the exarch of Ravenna. See exarchate.
2. n. In the early church, a prelate presiding over a diocese: as, the exarch of Ephesus. The title is often used as synonymous with patriarch; but strictly the exarch was inferior in rank and power to the patriarch, and superior to the metropolitan.
3. n. In the Gr. Ch., a legate of a patriarch, whose duty it is to sustain the authority of the patriarch, and to obtain accurate information concerning the lives of the clergy, ecclesiastical observances, monastic discipline, etc., in the provinces assigned to him. The power of the exarchs is very great. They can absolve, depose, or excommunicate in the name of the patriarch.

Wiktionary

1. n. historical In the Byzantine Empire, a governor of a distant province.
2. n. In the Eastern Christian Churches, the deputy of a patriarch, or a bishop who holds authority over other bishops without being a patriarch.
3. n. In these same churches, a bishop appointed over a group of the faithful not yet large enough or organized enough to constitute an eparchy or diocese.

GNU Webster's 1913

1. n. A viceroy; in Ravenna, the title of the viceroys of the Byzantine emperors; in the Eastern Church, the superior over several monasteries; in the modern Greek Church, a deputy of the patriarch , who visits the clergy, investigates ecclesiastical cases, etc.

WordNet 3.0

1. n. a bishop in one of several Eastern Orthodox Churches in North America
2. n. a bishop in eastern Christendom who holds a place below a patriarch but above a metropolitan
3. n. a viceroy who governed a large province in the Roman Empire