Unappealing sight (7)
I believe the answer is:
eyesore
'unappealing sight' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for eyesore that I've seen before include "Ugly sight, not nice to see" , "Blight" , "Ugly structure" , "Ugly prospect" , "horror" .)