adj. 25B6; verb
Austria tried to mediate between the belligerents : ARBITRATE, conciliate, moderate, act as peacemaker, make peace; intervene, step in, intercede, act as an intermediary, liaise.
a tribunal was set up to mediate disputes : RESOLVE, settle, arbitrate in, umpire, reconcile, referee; mend, clear up; informal patch up.
he attempted to mediate a solution to the conflict : NEGOTIATE, bring about, effect; formal effectuate.