Snug retreat (4)
I believe the answer is:
nest
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">snug retreat</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 nest that I've seen before include "breeding-ground" , "Avian structure" , "home for 22d [VIPERS]" , "Eyrie" , "Casually thrown" .)