A stoat in winter (6)
I believe the answer is:
ermine
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">a stoat in winter</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 ermine that I've seen before include "special trimmings" , "garb for nobility" , "Expensive white fur" , "'Trimming on royal robes, say (6)'" , "White fur of weasel" .)