squash vs summer squash

squash and summer squash both are nouns.

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

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

squash: edible fruit of a squash plant; eaten as a vegetable
summer squash: any of various fruits of the gourd family that mature during the summer; eaten while immature and before seeds and rind harden

Other hyponyms of squash include winter squash.

As nouns, summer squash is a hyponym of squash; that is, summer 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
summer squash: any of various usually bushy plants producing fruit that is eaten while immature and before the rind or seeds harden

squash (noun)	summer 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 that mature during the summer; eaten while immature and before seeds and rind harden
edible fruit of a squash plant; eaten as a vegetable	any of various usually bushy plants producing fruit that is eaten while immature and before the rind or seeds harden
any of numerous annual trailing plants of the genus Cucurbita grown for their fleshy edible fruits

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