numerosity vs multiplicity

numerosity and multiplicity both are nouns.

Word	Noun	Adjective	Verb	Adverb
numerosity	Yes	No	No	No
multiplicity	Yes	No	No	No

As nouns, numerosity and multiplicity are synonyms defined as:

Other synonyms of numerosity include numerousness.

numerosity (noun)	multiplicity (noun)
a large number	a large number
	the property of being multiple