mobster vs crook

mobster and crook both are nouns.

Word	Noun	Adjective	Verb	Adverb
mobster	Yes	No	No	No
crook	Yes	No	Yes	No

As nouns, crook is a hypernym of mobster; that is, crook is a word with a broader meaning than mobster:

mobster: a criminal who is a member of gang
crook: someone who has committed a crime or has been legally convicted of a crime

Other hypernyms of mobster include criminal, felon, malefactor, outlaw.

mobster (noun)	crook (noun)
a criminal who is a member of gang	a long staff with one end being hook shaped
	someone who has committed a crime or has been legally convicted of a crime
	a circular segment of a curve

mobster (verb)	crook (verb)
	bend or cause to bend