More cunning (5)
I believe the answer is:
slyer
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">more cunning</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 slyer that I've seen before include "More cunning" , "more sneaky" .)