Somewhat horrendous demise (3)
I believe the answer is:
end
'demise' is the definition.
(I've seen this in another clue)
'somewhat horrendous' is the wordplay.
'somewhat' says the answer is hidden in the clue.
'END' is hidden within 'horrendous'.
(Other definitions for end that I've seen before include "Goal; destruction" , "Novel by Graham Greene" , "Finish, close" , "target" , "Cesation, conclusion" .)