melon tree vs papaia

melon tree and papaia both are nouns.

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

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

melon tree and papaia: 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, papaya, papaya tree, pawpaw.

melon tree (noun)	papaia (noun)
tropical American shrub or small tree having huge deeply palmately cleft leaves and large oblong yellow fruit	tropical American shrub or small tree having huge deeply palmately cleft leaves and large oblong yellow fruit