underworld

noun3

1. •
   The world of the dead, located underneath the world of the living; the afterlife.

   • In Hindu scriptures, the four-eyed dogs Śārvara and Śyāma guard the underworld's entrance.
2. •
   That part of society that is engaged in crime or vice, and particularly those involved in organized crime.

   • A disproportionate amount of local politicians have connections to the underworld.
3. •
   The portion of a game that is set below ground.