War god somewhat miserable after uprising (4)
I believe the answer is:
ares
'war god' is the definition.
(I've seen this in another clue)
'somewhat miserable after uprising' is the wordplay.
'somewhat' indicates the answer is hidden within the clue.
'after uprising' says the letters should be written backwards (in a down clue, letters go up).
'sera' is hidden within 'miserable'.
'sera' back-to-front is 'ARES'.
(Other definitions for ares that I've seen before include "Land measures" , "Olympian" , "Greek god of war" , "figure of worship" , "Belligerent god" .)