Mafia UK /ˈmæfi.ə/US /ˈmɑfi.ə/ noun3 •The Mob: any particular mafia, mentioned uniquely within the discussion's established or implicit context, usually and especially the Sicilian-Italian–Italian-American one (especially in American English) but occasionally others (e.g., the Russian one, the Japanese one). •The international criminal organization of Sicilian origin operating in Italy and the United States. •Any other specific organized crime syndicate operating internationally in high-level organized crime; often with a modifying adjective, such as a nationality.Somehow he managed to upset the Russian Mafia.