Insult, affront (6)
I believe the answer is:
offend
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">insult</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I know that insult is a kind of offend)</span><br/ ><br/ >'<span class="explanation-format__original">affront</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ ></span>
(Other definitions for offend that I've seen before include "Commit an illegal act" , "Affront - break the law" , "Outrage" , "cause displeasure or do wrong" , "Annoy - upset" .)