Beat, drub (7)
I believe the answer is:
trounce
I believe this clue is a double definition.
'beat' is the first definition.
(I know that beat can be written as trounce)
'drub' is the second definition.
(I know that drub is a more specific form of the action the trounce)
(Other definitions for trounce that I've seen before include "summons" , "tank" , "Beat resoundingly" , "Massacre" , "Thoroughly defeat" .)