Harsh order (6)
I believe the answer is:
diktat
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">harsh order</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 diktat that I've seen before include "Strict order" , "Dogmatic statement" , "Declaration allowing no opposition" , "arbitrary order" , "Categorical statement" .)