Stopper; bribe (4)
I believe the answer is:
bung
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">stopper</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I know that bung is a type of stopper)</span><br/ ><br/ >'<span class="explanation-format__original">bribe</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ ></span>
(Other definitions for bung that I've seen before include "sweetener" , "Bribe (slang)" , "Stopper for closing hole in barrel" , "could be a corker" , "Cask stopper" .)