Harsh in manner (8)
I believe the answer is:
abrasive
'harsh in manner' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for abrasive that I've seen before include "Pumice, for example" , "Grinding substance" , "Like pumice - rough in manner" , "Harsh in manner, capable of causing anger" , "Tending to grind down" .)