Sponge feature (4)
I believe the answer is:
pore
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">sponge feature</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 pore that I've seen before include "Tiny opening in the skin" , "Minute passage in skin" , "Closely study" , "Rope around the skin-opening" , "Small hole" .)