Sound sozzled (4)
I believe the answer is:
slur
'sound sozzled' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for slur that I've seen before include "Negative comment" , "It's not clear, so to speak" , "Slight - mark on music" , "Slight - smear" , "Slight; blur" .)