underworld

As a noun underworld

is that part of society that is engaged in crime or vice.

As a proper noun Naraka is

the underworld or Hell according to Hinduism, Sikhism, Jainism and Buddhism, where souls are sent for the expiation of their sins.

As a noun underworld

is (underworld).

As a proper noun avernus is

the entrance to hell or the underworld, or the underworld itself.

As nouns the difference between underworld and undernet

is that underworld is (underworld) while undernet is the criminal underworld in cyberspace.

As a noun underworld

is that part of society that is engaged in crime or vice.

As a proper noun Demogorgon is

a pagan god or demon, associated with the underworld and envisaged as a powerful primordial being, whose very name was taboo; an incubus.