A tool for pounding (6)
I believe the answer is:
pestle
'a tool for pounding' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for pestle that I've seen before include "It grinds in a mortar" , "Kitchen item" , "Club for grinding" , "Grinder for mortar" , "Mortar's partner?" .)