crowd vs assemble

crowd is a noun but assemble is not a noun.

Word	Noun	Adjective	Verb	Adverb
crowd	Yes	No	Yes	No
assemble	No	No	Yes	No

As verbs, assemble is a hypernym of crowd; that is, assemble is a word with a broader meaning than crowd:

Other hypernyms of crowd include foregather, forgather, gather, meet.

crowd (noun)	assemble (noun)
a large number of things or people considered together
an informal body of friends

crowd (verb)	assemble (verb)
to gather together in large numbers	create by putting components or members together
cause to herd, drive, or crowd together	collect in one place
approach a certain age or speed	get people together
fill or occupy to the point of overflowing