Chin dimple (5)
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">chin dimple</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 cleft that I've seen before include "Split or indentation" , "Chin split" , "Split; fissure" , "Space" , "Opening, fissure" .)