Cutting, incisive (9)
I believe the answer is:
trenchant
I believe this clue is a double definition.
'cutting' is the first definition.
(I've seen this before)
'incisive' is the second definition.
(I've seen this before)
(Other definitions for trenchant that I've seen before include "Incisive in style" , "blunt" , "Incisive in expression" , "Forceful" , "biting" .)