crookneck vs yellow squash

crookneck and yellow squash both are nouns.

Word	Noun	Adjective	Verb	Adverb
crookneck	Yes	No	No	No
yellow squash	Yes	No	No	No

As nouns, yellow squash is a hypernym of crookneck; that is, yellow squash is a word with a broader meaning than crookneck:

crookneck: yellow squash with a thin curved neck and somewhat warty skin
yellow squash: squash having yellow skin and yellowish flesh and usually elongated neck

crookneck (noun)	yellow squash (noun)
yellow squash with a thin curved neck and somewhat warty skin	squash having yellow skin and yellowish flesh and usually elongated neck
	any of various squash plants grown for their yellow fruits with somewhat elongated necks