Coward say Trotsky upset (4)
I believe the answer is:
noel
'coward say' is the definition.
(playwright Noel Coward is an example)
'trotsky upset' is the wordplay.
'trotsky' becomes 'leon' (I've seen this in another clue).
'upset' shows that the letters should be reversed in order.
'leon' backwards is 'NOEL'.
(Other definitions for noel that I've seen before include "Festivity" , "present time" , "Yuletide" , "See 7 Across" , "seasonal festival" .)