mafia

Short definition from Wiktionary

Noun

1. 1
   A hierarchically structured secret organisation engaged in illegal activities like distribution of narcotics, gambling and extortion.
2. 2
   A crime syndicate.
3. 3
   A trusted group of associates, as of a political leader.
4. 4
   An entity which attempts to control a specified arena by violence or threats.

Proper noun

1. 1
   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.
2. 2
   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): Any other specific organized crime syndicate operating internationally in high-level organized crime; often with a modifying adj
3. 3
   A social deduction party game modelling a conflict between an informed minority (the mafia) and an uninformed majority (the innocents). Each player is secretly assigned a role within one of these teams, and the innocents attempt to identify the mafia members before they are all "murdered".