Underground conduit (5)
I believe the answer is:
sewer
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">underground conduit</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for sewer that I've seen before include "Disposal outlet" , "dressmaker?" , "Drainage conduit" , "Channel to carry away waste water and matter" , "One plying needle; drain" .)