pope (n.)
Old English papa (9c.), from Church Latin papa "bishop, pope" (in classical Latin, "tutor"), from Greek papas "patriarch, bishop," originally "father." Applied to bishops of Asia Minor and taken as a title by the Bishop of Alexandria c.250. In Western Church, applied especially to the Bishop of Rome since the time of Leo the Great (440-461) and claimed exclusively by them from 1073 (usually in English with a capital P-). Popemobile, his car, is from 1979. Papal, papacy, later acquisitions in English, preserve the original vowel.