The Hadean eon; part of the Precambrian supereon, spanning from around 4.6 to 4 billion years ago.
Pertaining to Hades or hell.
Of, or relating to the geological eon.
That part of society that is engaged in crime or vice.
The portion of a game that is set below ground.
The world of the dead, located underneath the world of the living; the afterlife.