Act as go-between (6)
I believe the answer is:
liaise
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">act as go-between</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for liaise that I've seen before include "Communicate with for mutual benefit" , "Mediate" , "Ast as go-between" , "Form a link (with)" , "Keep in touch to co-operate on something" .)