Church decree (5)
I believe the answer is:
canon
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">church decree</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for canon that I've seen before include "Standard" , "Body of works" , "priest for cathedral duties" , "Such literary works are genuine" , "Church decree or law" .)