An archimandrite is a senior monastic priest in the Eastern churches, originally the head of a monastery or of several, and now more often an honorific granted to distinguished celibate priests.
Head of the monasteries
The title originally denoted the head of a monastery or the superior set over several monasteries, so the archimandrite was in origin an office of monastic leadership, the counterpart in the East of the abbot, charged with the government of a monastic community. The word carries this sense of a senior monastic superior, and in that use it names a real office of authority over the monastic life.
An honorific for the celibate clergy
In modern usage the title has become more often an honorific granted to distinguished celibate priests, especially those in line for elevation to the episcopate, since bishops in the Eastern churches are drawn from the celibate monastic clergy, so the rank of archimandrite frequently marks a senior monk-priest of standing rather than the actual head of a monastery. The office thus spans the government of monasteries and the honouring of eminent celibate clergy. Entry is by appointment to the monastic office or by the granting of the honorific. The archimandrite represents the senior monastic priesthood of the Eastern churches, and the title, whether it marks the head of a monastery or an honoured celibate priest, belongs to the monastic clergy from whom the bishops of these churches are chosen, standing between the ordinary monk-priest and the episcopate.