Word Origin & History
"soft food for infants," c.1430, from O.Fr. papa "watered gruel," from L. pappa, a widespread word in children's language for "food" (e.g. M.H.G., Du. pap, Ger. Pappe), imitative of an infant's noise when hungry; possibly associated with pap (2) (q.v.). Meaning "over-simplified idea" first recorded 1548.
"nipple of a woman's breast," c.1200, first attested in Northern and Midlands writing, probably from a Scand. source (not recorded in O.N., but cf. dial. Swed. pappe), from PIE imitative base *pap- "to swell" (cf. L. papilla "nipple," papula "a swelling, pimple;" Lith. papas "nipple").