squash vs winter squash

squash and winter squash both are nouns.

Word	Noun	Adjective	Verb	Adverb
squash	Yes	No	Yes	No
winter squash	Yes	No	No	No

As nouns, winter squash is a hyponym of squash; that is, winter squash is a word with a more specific, narrower meaning than squash:

squash: edible fruit of a squash plant; eaten as a vegetable
winter squash: any of various fruits of the gourd family with thick rinds and edible yellow to orange flesh that mature in the fall and can be stored for several months

Other hyponyms of squash include summer squash.

As nouns, winter squash is a hyponym of squash; that is, winter squash is a word with a more specific, narrower meaning than squash:

squash: any of numerous annual trailing plants of the genus Cucurbita grown for their fleshy edible fruits
winter squash: any of various plants of the species Cucurbita maxima and Cucurbita moschata producing squashes that have hard rinds and mature in the fall

squash (noun)	winter squash (noun)
a game played in an enclosed court by two or four players who strike the ball with long-handled rackets	any of various fruits of the gourd family with thick rinds and edible yellow to orange flesh that mature in the fall and can be stored for several months
edible fruit of a squash plant; eaten as a vegetable	any of various plants of the species Cucurbita maxima and Cucurbita moschata producing squashes that have hard rinds and mature in the fall
any of numerous annual trailing plants of the genus Cucurbita grown for their fleshy edible fruits

squash (verb)	winter squash (verb)
to compress with violence, out of natural shape or condition