Pencil topper (6)
I believe the answer is:
eraser
'pencil topper' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for eraser that I've seen before include "One removes writing" , "destroyer" , "A student's rubber, or the one who uses it" , "Correcting implement used in drawing or writing" , "Item used for rubbing out" .)