green-eyed monster vs jealousy

green-eyed monster and jealousy both are nouns.

Word	Noun	Adjective	Verb	Adverb
green-eyed monster	Yes	No	No	No
jealousy	Yes	No	No	No

As nouns, green-eyed monster and jealousy are synonyms defined as:

green-eyed monster and jealousy: a feeling of jealous envy (especially of a rival)

green-eyed monster (noun)	jealousy (noun)
a feeling of jealous envy (especially of a rival)	zealous vigilance
	a feeling of jealous envy (especially of a rival)