rambotan vs fruit tree

rambotan and fruit tree both are nouns.

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

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

rambotan (noun)	fruit tree (noun)
pleasantly acid bright red oval Malayan fruit covered with soft spines	tree bearing edible fruit
Malayan tree bearing spiny red fruit