Long tube (4)
I believe the answer is:
pipe
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">long tube</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for pipe that I've seen before include "chanter" , "Tube, maybe musical" , "Tropical fruit" , "Tube to carry water, gas etc" , "It can be played or smoked" .)