Authoritative decision (6)
I believe the answer is:
ruling
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">authoritative decision</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 ruling that I've seen before include "Judge's decision" , "judgment" , "Exercising power or authority" , "Decision as of judge" , "Decree" .)