Smear; haze (4)
I believe the answer is:
blur
I believe this clue is a double definition.
'smear' is the first definition.
(I know that smear can be written as blur)
'haze' is the second definition.
(I've seen this before)
(Other definitions for blur that I've seen before include "Rock band - make less clear" , "Confused impression" , "Make or become indistinct" , "Unfocused image" , "Out-of-focus sight" .)