Wind battering ten rowers (9)
I believe the answer is:
norwester
'wind' is the definition.
(I've seen this before)
'battering ten rowers' is the wordplay.
'battering' indicates anagramming the letters.
'ten'+'rowers'='tenrowers'
'tenrowers' with letters rearranged gives 'NORWESTER'.
(Other definitions for norwester that I've seen before include "Liquor" , "Wind" , "Oilskin" .)