Negative impression? (4)
I believe the answer is:
dent
'negative impression?' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for dent that I've seen before include "Hollow from impact" , "Tend to make small depression" , "Hollow, depression" , "tooth (13) [FRENCH]" , "Depression caused by blow" .)