cashew tree vs nut tree

cashew tree and nut tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
cashew tree	Yes	No	No	No
nut tree	Yes	No	No	No

As nouns, nut tree is a hypernym of cashew tree; that is, nut tree is a word with a broader meaning than cashew tree:

cashew tree: tropical American evergreen tree bearing kidney-shaped nuts that are edible only when roasted
nut tree: tree bearing edible nuts

cashew tree (noun)	nut tree (noun)
tropical American evergreen tree bearing kidney-shaped nuts that are edible only when roasted	tree bearing edible nuts