Show mercy (6)
I believe the answer is:
relent
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">show mercy</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for relent that I've seen before include "Acquiesce" , "'Give in, soften (6)'" , "Soften, grow less severe" , "Become less severe, soften" , "Relax severity or opposition" .)