Mandibles (4)
I believe the answer is:
jaws
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">mandibles</span>' is the definition.<br/ ><span class="explanation-format__explanation">(thesaurus)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for jaws that I've seen before include "Film about sharks" , "has a lot to say" , "lectures" , "frightening film" , "rabbits" .)