Cunning, deceitful (3)
I believe the answer is:
sly
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">cunning</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I know that cunning can be written as sly)</span><br/ ><br/ >'<span class="explanation-format__original">deceitful</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ ></span>
(Other definitions for sly that I've seen before include "Crafty, devious" , "'Cunning, wily (3)'" , "Doing things in unpleasant and secret way" , "Cunning, deceitful" , "Artful" .)