Duck from which down is obtained (5)
I believe the answer is:
eider
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">duck from which down is obtained</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for eider that I've seen before include "Duck providing fine down" , "Sea duck with soft down" , "Northern sea duck" , "Downy sea duck" , "Down comes from this" .)