mamey vs fruit tree

mamey and fruit tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
mamey	Yes	No	No	No
fruit tree	Yes	No	No	No

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

mamey (noun)	fruit tree (noun)
globular or ovoid tropical fruit with thick russet leathery rind and juicy yellow or reddish flesh	tree bearing edible fruit
tropical American tree having edible fruit with a leathery rind