Chess win
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">chess win</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for mate that I've seen before include "Perhaps the wife" , "Final check at chess" , "Team (anag.)" , "Companion, wife" , "Pal on team" .)