cashew nut vs edible nut

cashew nut and edible nut both are nouns.

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

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

cashew nut: 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 nut (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