Plundering coarse material (7)
I believe the answer is:
sacking
This clue is a double definition.
'plundering' is the first definition.
('sack' can be a synonym of 'plunder')
'coarse material' is the second definition.
(I've seen this before)
(Other definitions for sacking that I've seen before include "Dismissal (from job)" , "Coarse stuff" , "Dismissing (from post)" , "P45" , "Terminating someone's employment" .)