hoi polloi vs masses

hoi polloi and masses both are nouns.

Word	Noun	Adjective	Verb	Adverb
hoi polloi	Yes	No	No	No
masses	Yes	No	No	No

As nouns, hoi polloi and masses are synonyms defined as:

Other synonyms of hoi polloi include mass, multitude, people, the great unwashed.

hoi polloi (noun)	masses (noun)
the common people generally	the common people generally