cocoa plum vs fruit tree

cocoa plum and fruit tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
cocoa plum	Yes	No	No	No
fruit tree	Yes	No	No	No

As nouns, fruit tree is a hypernym of cocoa plum; that is, fruit tree is a word with a broader meaning than cocoa plum:

cocoa plum (noun)	fruit tree (noun)
plum-shaped whitish to almost black fruit used for preserves; tropical American	tree bearing edible fruit
small tropical American tree bearing edible plumlike fruit