Offensive sight (7)
I believe the answer is:
eyesore
'offensive sight' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for eyesore that I've seen before include "Ugly sight, not nice to see" , "Ugly item" , "Blight" , "A monstrous carbuncle" , "pigsty" .)