Legal matter (3)
I believe the answer is:
res
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">legal matter</span>' is the definition.<br/ ><span class="explanation-format__explanation">(legal term for a thing)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for res that I've seen before include "Notes" , "Latin thing" , "reservation" , "land specially set aside" , "Object" .)