Cause harm to (6)
I believe the answer is:
injure
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">cause harm to</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for injure that I've seen before include "Wrong" , "Cause harm" , "Hurt or wound" , "Do harm to someone" , "Cause hurt, damage" .)