Pumpkin and Winter squash

Pumpkin noun - A coarse vine widely cultivated for its large pulpy round orange fruit with firm orange skin and numerous seeds; subspecies of Cucurbita pepo include the summer squashes and a few autumn squashes.

Winter squash and pumpkin are semantically related. In some cases you can use "Winter squash" instead a noun "Pumpkin".

Winter squash noun - Any of various plants of the species Cucurbita maxima and Cucurbita moschata producing squashes that have hard rinds and mature in the fall.

Pumpkin and winter squash are semantically related. You can use "Pumpkin" instead a noun phrase "Winter squash".