Depletion (5)
I believe the answer is:
drain
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">depletion</span>' is the definition.<br/ ><span class="explanation-format__explanation">(drain is a kind of depletion)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for drain that I've seen before include "Something using up resources" , "Nadir (anag.)" , "See 11 dn" , "Culvert" , "Gutter" .)