Thump counter furiously (7)
I believe the answer is:
trounce
'thump' is the definition.
(I've seen this before)
'counter furiously' is the wordplay.
'furiously' is an anagram indicator.
'counter' anagrammed gives 'TROUNCE'.
(Other definitions for trounce that I've seen before include "Flog" , "National flower of South Africa" , "Destroy" , "Defeat heavily in recount" , "Beat heavily" .)