Thick stick as weapon (6)
I believe the answer is:
cudgel
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">thick stick as weapon</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 cudgel that I've seen before include "Heavy stick or club as a weapon" , "(Strike with a) heavy stick" , "Stout stick used as a weapon" , "Heavy staff, club" , "brain" .)