1. a chief priest.
2. Judaism. (from Aaronic times to about the 1st century A.D.) the priest ranking above all other priests and the only one permitted to enter the holy of holies.
3. Informal. a person in a high position of power or influence, esp. one who is revered as a preeminent authority or interpreter: the high priest of the young painters.
[ 1350-1400; ME heiye prest ]