Arbitrate (7)
I believe the answer is:
mediate
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">arbitrate</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for mediate that I've seen before include "Help settle a dispute" , "try to resolve dispute" , "Act as negotiator between opposing side" , "ie Tamed (anag.)" , "Intervene, act as go-between" .)