Flue (7)
I believe the answer is:
chimney
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">flue</span>' is the definition.<br/ ><span class="explanation-format__explanation">(chimney is a kind of flue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for chimney that I've seen before include "Smoke pipe; rock cleft" , "Smoker on the roof?" , "Father Christmas's entry?" , "funnel" , "Flue" .)