melon vs edible fruit

melon and edible fruit both are nouns.

Word	Noun	Adjective	Verb	Adverb
melon	Yes	No	No	No
edible fruit	Yes	No	No	No

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

melon: any of numerous fruits of the gourd family having a hard rind and sweet juicy flesh
edible fruit: edible reproductive body of a seed plant especially one having sweet flesh

melon (noun)	edible fruit (noun)
any of numerous fruits of the gourd family having a hard rind and sweet juicy flesh	edible reproductive body of a seed plant especially one having sweet flesh
any of various fruit of cucurbitaceous vines including: muskmelons, watermelons, cantaloupes, cucumbers