"father," 1681, from Fr. papa, from L. papa, originally a child's word, cf. Gk. pappa (voc.) "o father," pappas "father," pappos "grandfather." The native word is daddy; first use of papa was in courtly speech, as a continental affectation, not used by common folk until late 18c.
[pah-puh, puh-pah] 
) a code word used in communications, esp. by radio, to represent the letter P.