come on vs crowd

come on is not a noun while crowd is a noun.

Word	Noun	Adjective	Verb	Adverb
come on	No	No	Yes	No
crowd	Yes	No	Yes	No

As verbs, crowd is a hyponym of come on; that is, crowd is a word with a more specific, narrower meaning than come on:

Other hyponyms of come on include drive up, bear down on, bear down upon, edge in, edge up, close, push.

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

come on (verb)	crowd (verb)
occur or become available	to gather together in large numbers
appear or become visible; make a showing	cause to herd, drive, or crowd together
develop in a positive way	approach a certain age or speed
start running, functioning, or operating	fill or occupy to the point of overflowing
move towards