Synonyms for Mafia (same or very similar meaning)
WordNet sense 1 (a crime syndicate in the United States; organized in families; believed to have important relations to the Sicilian Mafia):
Maffia, Cosa NostraWordNet sense 2 (a secret terrorist group in Sicily; originally opposed tyranny but evolved into a criminal organization in the middle of the 19th century):
Sicilian MafiaFrom the ODE community, based on WordNetadd/edit