Japanese assassin (5)
I believe the answer is:
ninja
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">japanese assassin</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for ninja that I've seen before include "Japanese expert in stealth and martial arts" , "Assassins" , "Assassin from Japan" , "Eastern agent" , "Medieval Japanese trained in martial arts, assassination and espionage" .)