mammee apple vs fruit tree

mammee apple and fruit tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
mammee apple	Yes	No	No	No
fruit tree	Yes	No	No	No

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

mammee apple: tropical American tree having edible fruit with a leathery rind
fruit tree: tree bearing edible fruit

mammee apple (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