Counter-revolutionary clobber (7)
I believe the answer is:
trounce
'clobber' is the definition.
(I know that clobber is a kind of the trounce)
'counter-revolutionary' is the wordplay.
'revolutionary' is an anagram indicator.
'counter' with letters rearranged gives 'TROUNCE'.
(Other definitions for trounce that I've seen before include "tank" , "Thump" , "Beat roundly" , "Clobber" , "Beat soundly" .)