Church decree or law (5)
I believe the answer is:
canon
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">church decree</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >'<span class="explanation-format__original">law</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ ></span>
(Other definitions for canon that I've seen before include "Principle; list of recognised works" , "Round, general rule" , "accepted criterion" , "Collection of writing" , "Body of established rules or principles" .)