Smiled derisively
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">smiled derisively</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 sneered that I've seen before include "Ridiculed" , "Mocked contemptuously" , "Smiled contemptuously" , "Showed contempt" , "Was contemptuous" .)