Obscurity (8)
I believe the answer is:
oblivion
'obscurity' is the definition.
(I know that oblivion is a type of obscurity)
This is the entire clue.
(Other definitions for oblivion that I've seen before include "State of being altogether forgotten" , "Total extinction" , "State of being forgotten and disregarded" , "State of being mentally withdrawn or blank" , "State of unawareness" .)