Beaver's den (5)
I believe the answer is:
lodge
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">beaver's den</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for lodge that I've seen before include "small house alongside park" , "See 2" , "Settle" , "Small gatehouse" , "Stay (somewhere) temporarily" .)