"father," 1680s, from French papa, from Latin papa, originally a reduplicated child's word, similar to Greek pappa (vocative) "o father," pappas "father," pappos "grandfather." The native word is daddy; according to OED the first use of papa was in courtly speech, as a continental affectation, and it was not used by common folk until late 18c.
"father," 1838, chiefly American English, shortened from papa (1680s), from French papa, from Old French, a children's word, similar to Latin pappa (see papa). Form poppa is recorded from 1897.
"a father, papa," recorded from c. 1500, but probably much older, from child's speech, nearly universal and probably prehistoric (compare Welsh tad, Irish daid, Lithuanian tėtė, Sanskrit tatah, Czech tata, Latin tata "father," Greek tata, used by youths to their elders). Compare papa.
"the Bishop of Rome as head of the Roman Catholic Church," c. 1200, from Old English papa (9c.), from Church Latin papa "bishop, pope" (in classical Latin, "tutor"), from Greek papas "patriarch, bishop," originally "father" (see papa).
Applied to bishops of Asia Minor and taken as a title by the Bishop of Alexandria c. 250. In the Western Church, applied especially to the Bishop of Rome since the time of Leo the Great (440-461), the first great asserter of its privileges, and claimed exclusively by them from 1073 (usually in English with a capital P-). Popemobile, his car, is from 1979. Pope's nose for "fleshy part of the tail of a bird" is by 1895. Papal, papacy, later acquisitions in English, preserve the original vowel.
"of a pope, relating to a pope in his official capacity," late 14c., from Old French papal (late 14c.) and directly from Medieval Latin papalis "pertaining to the pope," from papa (see pope).
late 14c., papacie, "the office or jurisdiction of a pope," from Medieval Latin papatia "papal office," from Late Latin papa "pope" (see pope). Old English had papdom in this sense. Meaning "the succession or line of popes; the system of ecclesiastical government based upon authority of the Bishop of Rome over the Church" is from 1540s.
1530s, "adherent of the pope, one who acknowledges the supreme authority of the Church of Rome," from French papiste, from papa "pope," from Church Latin papa (see pope). Historically usually a term of anti-Catholic opprobrium. Related: Papism.