Self-defence (6)
I believe the answer is:
aikido
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">self-defence</span>' is the definition.<br/ ><span class="explanation-format__explanation">(aikido is a kind of self-defence)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for aikido that I've seen before include "Martial art, akin to judo" , "one of the martial arts" , "Japanese form of self-defence" , "Japanese martial art similar to judo" , "Defensive moves" .)