Offensive remark (6)
I believe the answer is:
insult
'offensive remark' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for insult that I've seen before include "Slander" , "Demeaning remark" , "Speak rudely or offensively about" , "Treat with contempt" , "Speak to or treat with disrespect" .)