gangster's moll vs gun moll

gangster's moll and gun moll both are nouns.

Word	Noun	Adjective	Verb	Adverb
gangster's moll	Yes	No	No	No
gun moll	Yes	No	No	No

As nouns, gangster's moll and gun moll are synonyms defined as:

Other synonyms of gangster's moll include moll.

gangster's moll (noun)	gun moll (noun)
the girlfriend of a gangster	the girlfriend of a gangster