Strike repeatedly (6)
I believe the answer is:
batter
'strike repeatedly' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for batter that I've seen before include "Hit hard and often, subject to repeated violence" , "Yorkshire pudding and cricket both require this" , "Strike violently and repeatedly" , "Fish may be fried in this coating" , "Clobber" .)