gangster vs yardie

gangster and yardie both are nouns.

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

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

gangster: 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 gangster include apache, yakuza.

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