Thayer's Greek Lexicon

 1. name Hades or Pluto, the god of the lower regions
2. Orcus, the nether world, the realm of the dead
3. later use of this word: the grave, death, hell

In Biblical Greek it is associated with Orcus, the infernal regions,
a dark and dismal place in the very depths of the earth, the common
receptacle of disembodied spirits. Usually Hades is just the abode of
the wicked, Lu. 16:23, Rev. 20:13,14; a very uncomfortable place. TDNT.