Second European defends abuse over guitarist originally in Blur (6)
I believe the answer is:
smudge
'blur' is the definition.
(I know that blur can be written as smudge)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for smudge that I've seen before include "Blur, blot" , "A smeared mark or stain" , "Make blurred" , "blurred impression" , "Smeared blot" .)