netherworld

• nether world

From nether- (“beneath, lower”) +‎ world.

netherworld

1. The place to which one's spirit descends upon death, conceived as below the surface of the earth.

   In some religions, one's soul departs to a netherworld, hell, instead of the heavens.

2. The locale of the spirit world or afterlife, whether deemed to be situated below the world of the living or not.

   While I was astrally projecting, I felt my soul pass through many insubstantial netherworlds.

3. Specifically, a location of punishment in the afterlife; a hell.

   The missionary was motivated by a sincere desire to rescue souls from eternal torment in the netherworld.

4. (by extension) A hidden, shadowy, or sinister subculture, such as that of organized crime.

   Richard had been initiated into the netherworld of dog racing by his father, and knew all the popular greyhound performance-enhancing drugs.

Depending on cultural context, it may be appropriate to construct this as the netherworld, if only one is supposed to exist.

• (subterranean region for spirits of the dead): Hades, hell, nether region, underworld
• (location of the spirit world or afterlife): astral plane, heaven
• (place of punishment after death): damnation, Hades, hell, underworld
• (hidden, shadowy, or sinister subculture): underworld