Systematic procedure (6)
I believe the answer is:
method
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">systematic procedure</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 method that I've seen before include "Systematic way of doing something" , "Mode, procedure" , "rule" , "Way of proceeding" , "Orderliness (of thought or behaviour)" .)