crowd vs mob

crowd and mob both are nouns.

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

As nouns, mob is a hyponym of crowd; that is, mob is a word with a more specific, narrower meaning than crowd:

Other hyponyms of crowd include army, crush, jam, press, drove, horde, swarm, huddle, rabble, rout, phalanx, flock, troop.

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

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

crowd (noun)	mob (noun)
a large number of things or people considered together	a disorderly crowd of people
an informal body of friends	an association of criminals
	a loose affiliation of gangsters in charge of organized criminal activities

crowd (verb)	mob (verb)
to gather together in large numbers	press tightly together or cram
cause to herd, drive, or crowd together
approach a certain age or speed
fill or occupy to the point of overflowing