Gaping mouth (3)
I believe the answer is:
maw
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">gaping mouth</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for maw that I've seen before include "Jaws or throat of a voracious animal" , "Mouth (animal's)" , "gulf" , "Mouth of a voracious animal - or an American mum?" , "Jaws or mouth of a voracious animal" .)