custard apple vs annon

custard apple and annon both are nouns.

Word	Noun	Adjective	Verb	Adverb
custard apple	Yes	No	No	No
annon	Yes	No	No	No

As nouns, annon is a hyponym of custard apple; that is, annon is a word with a more specific, narrower meaning than custard apple:

custard apple: the fruit of any of several tropical American trees of the genus Annona having soft edible pulp
annon: sweet pulpy tropical fruit with thick scaly rind and shiny black seeds

custard apple (noun)	annon (noun)
the fruit of any of several tropical American trees of the genus Annona having soft edible pulp	sweet pulpy tropical fruit with thick scaly rind and shiny black seeds
any of several tropical American trees bearing fruit with soft edible pulp