noun
boobies; breasts
Children's word for breasts; used by or to small children.
赤ちゃんが「パイパイ」と言ってお母さんの胸を指さした。
The baby said 'boobies' and pointed at its mother's chest.
Children's word for milk, often breast milk or formula.
お腹が空いたのか、子供が「パイパイちょうだい」と泣いている。
The child is crying, 'Give me milk,' probably hungry.