Underworld in Greek mythology (5)
I believe the answer is:
hades
'underworld in greek mythology' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for hades that I've seen before include "Underworld, hell" , "Infernal situation" , "It's classical hell in the shade" , "The nether world, hell" , "Home of the souls of the dead" .)