#underworld  the criminal class
  supertype:  socio-economic_class__class__clas__socialclas  people having the same social or economic status; "the working class"; "an emerging professional class"
  member:  organized_crime__organizedcrime__gangland__gangdom  underworld organizations
     member:  mob__gang__pack__ring  an association of criminals; "police tried to break up the gang"; "a pack of thieves"
        member:  gangster__mobster  a criminal who is a member of gang
  member:  racketeer  some who commits crimes for profit (especially one who obtains money by fraud or extortion)

No statement uses or specializes underworld; click here to add one.