papaw tree vs custard apple

papaw tree and custard apple both are nouns.

Word	Noun	Adjective	Verb	Adverb
papaw tree	Yes	No	No	No
custard apple	Yes	No	No	No

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

papaw tree: small tree native to the eastern United States having oblong leaves and fleshy fruit
custard apple: any of several tropical American trees bearing fruit with soft edible pulp

Other hypernyms of papaw tree include custard apple tree.

papaw tree (noun)	custard apple (noun)
small tree native to the eastern United States having oblong leaves and fleshy fruit	the fruit of any of several tropical American trees of the genus Annona having soft edible pulp
	any of several tropical American trees bearing fruit with soft edible pulp