Single combat (4)
I believe the answer is:
duel
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">single combat</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for duel that I've seen before include "Potentially fatal fight between two people" , "honourable affair" , "Contest between two with deadly weapons" , "One got satisfaction from this" , "Fight to the death between two people" .)