Stigma (4)
I believe the answer is:
slur
'stigma' 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 "Slight - stain" , "Mumble words - it's an affront" , "Disparaging remark" , "Stigma" , "Pronounce indistinctly - discredit" .)