Sewer (5)
I believe the answer is:
drain
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">sewer</span>' is the definition.<br/ ><span class="explanation-format__explanation">(drain can mean a sewer)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for drain that I've seen before include "Culvert" , "Siphon off" , "To empty (of fluid)" , "Draw off liquid" , "Wasted down here" .)