multitude vs grouping

multitude and grouping both are nouns.

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

As nouns, grouping is a hypernym of multitude; that is, grouping is a word with a broader meaning than multitude:

Other hypernyms of multitude include group.

multitude (noun)	grouping (noun)
a large gathering of people	any number of entities (members) considered as a unit
the common people generally	the activity of putting things together in groups
a large indefinite quantity	a system for classifying things into groups