The thick end (4)
I believe the answer is:
butt
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">the thick end</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for butt that I've seen before include "couple of hogsheads?" , "Stub" , ""bottom" to US" , "Large cask" , "Contralto" .)