Fish; weapon (4)
I believe the answer is:
pike
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">fish</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(pike is a kind of fish)</span><br/ ><br/ >'<span class="explanation-format__original">weapon</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that pike is a type of weapon)</span><br/ ><br/ ></span>
(Other definitions for pike that I've seen before include "Weapon on long shaft; Northern hill" , "Shafted weapon; diving position" , "Predatory freshwater fish" , "Fish - long spear-like weapon" , "Fresh-water fish or old spear" .)