A zek or tsar with wings clipped, backing coup (6)
I believe the answer is:
stroke
'coup' is the definition.
(I've seen this before)
'a zek or tsar with wings clipped backing' is the wordplay.
'with wings clipped' indicates the answer is hidden within the clue (the sides or wings of the clue must be removed).
'backing' shows that the letters should be reversed in order.
'ekorts' is hidden within 'zek or tsar'.
'ekorts' backwards is 'STROKE'.
(Other definitions for stroke that I've seen before include "Caress - rower" , "beat?" , "Brilliant achievement" , "Attack of paralysis found in a boat?" , "Mark - oarsman - blow - apoplexy" .)