hades

(Greek: the lower world [originally, invisible, to make invisible])

Hadean
A descriptive word meaning place of the dead or hellish.
hadephobia
An abnormal fear of hell with the idea that one may go there after death and judgment day.
Hades
1. A Greek god whose name means, "The Unseen". He was lord of the underworld, the abode of the dead.
2. The Greek word Hades was used to translate several Hebrew words in the Bible, namely, "the pit, stillness, death, those who bring death, deep darkness", and, most commonly, Sheol.
3. In Homer, the name of the god of the lower world, but in later times transferred to his kingdom abode, or house, so that it became a name for the nether world; Greek, used to render Hebrew sheol, the abode of the dead or departed spirits.

Introduced into English use, about 1600, in connexion with theological controversies about the fifth article (on the third day brought to life from the dead) of the Apostles' Creed (a formula containing in brief statements, or "articles", the fundamental tenets of Christian belief, and having for its authors, according to tradition, the Twelve Apostles).
4. In Greek myth, the oldest name of the god of the dead, also called Pluto.
5. The kingdom of Hades, the lower world, the abode of departed spirits or shades.