Become less severe (6)
I believe the answer is:
relent
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">become less severe</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for relent that I've seen before include "Abandon cruel treatment" , "Back down" , "Give in to influence or pressure" , "Become less stern than intended" , "Come round" .)