Egg pouch (3)
I believe the answer is:
sac
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">egg pouch</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 sac that I've seen before include "Traditional entitlement to hold court" , "Bag-like cavity" , "Bag-like part of the body" , "Bladder" , "Bodily pouch" .)