butternut squash

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A type of winter squash (Cucurbita moschata) having a bell-like shape, a smooth tan rind, and edible yellow or orange flesh.

Wiktionary

1. n. Curcurbita moschata: a vase-shaped orange-fleshed hard winter squash.

WordNet 3.0

1. n. plant bearing buff-colored squash having somewhat bottle-shaped fruit with fine-textured edible flesh and a smooth thin rind
2. n. buff-colored squash with a long usually straight neck and sweet orange flesh