macadamia nut vs macadamia tree

macadamia nut and macadamia tree both are nouns.

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

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

macadamia nut: small Australian tree with racemes of pink flowers; widely cultivated (especially in Hawaii) for its sweet edible nuts
macadamia tree: any tree of the genus Macadamia

Other hypernyms of macadamia nut include macadamia.

macadamia nut (noun)	macadamia tree (noun)
nutlike seed with sweet and crisp white meat	any tree of the genus Macadamia
small Australian tree with racemes of pink flowers; widely cultivated (especially in Hawaii) for its sweet edible nuts