mafia (n.) Look up mafia at Dictionary.com
1875, from Italian Mafia "Sicilian secret society of criminals" (the prevailing sense outside Sicily), earlier, "spirit of hostility to the law and its ministers," from Italian (Sicilian) mafia "boldness, bravado," probably from Arabic mahjas "aggressive, boasting, bragging." Or perhaps from Old French mafler "to gluttonize, devour." A member is a mafioso (1870), fem. mafiosa, plural mafiosi.