melon tree vs papaya

melon tree and papaya both are nouns.

Word	Noun	Adjective	Verb	Adverb
melon tree	Yes	No	No	No
papaya	Yes	No	No	No

As nouns, melon tree and papaya are synonyms defined as:

melon tree and papaya: tropical American shrub or small tree having huge deeply palmately cleft leaves and large oblong yellow fruit

Other synonyms of melon tree include Carica papaya, papaia, papaya tree, pawpaw.

melon tree (noun)	papaya (noun)
tropical American shrub or small tree having huge deeply palmately cleft leaves and large oblong yellow fruit	large oval melon-like tropical fruit with yellowish flesh
	tropical American shrub or small tree having huge deeply palmately cleft leaves and large oblong yellow fruit