Heavy weapon (4)
(Other definitions for broadsword that I've seen before include "Wide-bladed weapon" , "cutting weapon" , "old weapon" , "cutter" , "means of attack" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">heavy 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 cosh that I've seen before include "Thick heavy stick as a weapon" , "Club used as a weapon" , "Blackjack" , "Personal weapon" , "Blunt weapon, often of hard rubber" .)