cashew vs edible nut

cashew and edible nut both are nouns.

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

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

cashew: kidney-shaped nut edible only when roasted
edible nut: a hard-shelled seed consisting of an edible kernel or meat enclosed in a woody or leathery shell

cashew (noun)	edible nut (noun)
kidney-shaped nut edible only when roasted	a hard-shelled seed consisting of an edible kernel or meat enclosed in a woody or leathery shell
tropical American evergreen tree bearing kidney-shaped nuts that are edible only when roasted