pistachio nut vs edible nut

pistachio nut and edible nut both are nouns.

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

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

pistachio nut: nut of Mediterranean trees having an edible green kernel
edible nut: a hard-shelled seed consisting of an edible kernel or meat enclosed in a woody or leathery shell

pistachio nut (noun)	edible nut (noun)
nut of Mediterranean trees having an edible green kernel	a hard-shelled seed consisting of an edible kernel or meat enclosed in a woody or leathery shell