Sty noise (4)
I believe the answer is:
oink
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">sty noise</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 oink that I've seen before include "it might be in a pen one hears" , "Piggish noise" , "behave like a pig" , "Pig's grunt" , "Sound made by a pig" .)