mobster vs yardie

mobster and yardie both are nouns.

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

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

mobster: a criminal who is a member of gang
yardie: member of an international gang of Jamaican criminals who sell drugs and violence

Other hyponyms of mobster include apache, yakuza.

mobster (noun)	yardie (noun)
a criminal who is a member of gang	member of an international gang of Jamaican criminals who sell drugs and violence