Abrasive sheet (9)
I believe the answer is:
sandpaper
'abrasive sheet' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for sandpaper that I've seen before include "Abrasive material" , "Means of smoothing wood" , "Abrasive smoother" , "Abrasive sheet (DIY)" , "Material used for smoothing" .)