Pig's grunt (4)
I believe the answer is:
oink
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">pig's grunt</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for oink that I've seen before include "Grunt by a pig" , "Farmyard sound" , "Grunting noise" , "Sound made by a pig" , "Sow's sound" .)