mediator
noun [ C ]
uk/ˈmiːdieɪtər/ usa person who tries to end a disagreement by helping the two sides to talk about and agree on a solution:
Lawyers acting for the companies held another meeting with mediators this week.
a federal/independent/UN mediator After talks reached an impasse last month, US federal mediators instituted a 30-day cooling-off period.
act/serve as mediator She has agreed to act as mediator and meet with the board to try to resolve the dispute.
See also
arbitrator