melon vs melon vine

melon and melon vine both are nouns.

Word	Noun	Adjective	Verb	Adverb
melon	Yes	No	No	No
melon vine	Yes	No	No	No

As nouns, melon and melon vine are synonyms defined as:

melon and melon vine: any of various fruit of cucurbitaceous vines including: muskmelons, watermelons, cantaloupes, cucumbers

melon (noun)	melon vine (noun)
any of numerous fruits of the gourd family having a hard rind and sweet juicy flesh	any of various fruit of cucurbitaceous vines including: muskmelons, watermelons, cantaloupes, cucumbers
any of various fruit of cucurbitaceous vines including: muskmelons, watermelons, cantaloupes, cucumbers