Gun; ransack (5)
I believe the answer is:
rifle
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">gun</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I know that rifle is a type of firearm)</span><br/ ><br/ >'<span class="explanation-format__original">ransack</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(rifle can mean to ransack or rob)</span><br/ ><br/ ></span>
(Other definitions for rifle that I've seen before include "Winchester" , "An arm" , "Rummage" , "Search and rob for army weapon" , "Gun; plunder" .)