pie melon
/ˈpʌɪ mɛlən/noun
1 US. A melon used as a filling for pies. Now historical.
2Any of several cucurbits, especially (a) NZ the fig-leaf gourd, Cucurbita ficifolia; (b) Australian the watermelon, Citrullus lanatus.
Origin
Mid 19th century. From pie + melon.