A pumpkin is a cultivated winter squash in the genus Cucurbita. The term is most commonly applied to round, orange-colored squash varieties, but does not possess a scientific definition. It may be used in reference to many different squashes of varied appearance and belonging to multiple species in the Cucurbita genus.
"Pumpkin" is sometimes used interchangeably with "squash" or "winter squash", and is commonly used for some cultivars of Cucurbita argyrosperma, Cucurbita ficifolia, Cucurbita maxima, Cucurbita moschata, and Cucurbita pepo.