Sly look (4)
I believe the answer is:
leer
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">sly look</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 leer that I've seen before include "Ogle, smirk" , "Stare suggestively" , "Lascivious gaze" , "Lecherous look" , "Look suggestively" .)