crowd together vs herd

crowd together is not a noun while herd is a noun.

Word	Noun	Adjective	Verb	Adverb
crowd together	No	No	Yes	No
herd	Yes	No	Yes	No

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

Other hyponyms of crowd together include mass, overcrowd, pour, pullulate, stream, swarm, teem, jam, mob, pack, pile, throng.

crowd together (noun)	herd (noun)
	a group of cattle or sheep or other domestic mammals all of the same kind that are herded by humans
	a group of wild mammals of one species that remain together: antelope or elephants or seals or whales or zebra
	a crowd especially of ordinary or undistinguished persons or things

crowd together (verb)	herd (verb)
to gather together in large numbers	move together, like a herd
	cause to herd, drive, or crowd together
	keep, move, or drive animals