Gloomy aura (4)
I believe the answer is:
pall
'gloomy aura' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for pall that I've seen before include "A dark cover; cease to interest" , "Lose interest" , "Cloth covering a coffin" , "Weary" , "shadow" .)