Dominates (5)
I believe the answer is:
rules
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">dominates</span>' is the definition.<br/ ><span class="explanation-format__explanation">('rule' can be a synonym of 'dominate')</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for rules that I've seen before include "Laws; draws lines" , "following Queensberry?" , "strips" , "Australian football" , "governments" .)