multitude vs plurality

multitude and plurality both are nouns.

Word	Noun	Adjective	Verb	Adverb
multitude	Yes	No	No	No
plurality	Yes	No	No	No

As nouns, multitude and plurality are synonyms defined as:

Other synonyms of multitude include battalion, large number, pack.

multitude (noun)	plurality (noun)
a large gathering of people	(in an election with more than 2 options) the number of votes for the candidate or party receiving the greatest number (but less than half of the votes)
the common people generally	a large indefinite quantity
a large indefinite quantity	the state of being plural