simple past tense and past participle of mediate
"The diplomat mediated a peaceful agreement between the two warring nations before returning to his home country."
In plain English: Mediated means to act as an intermediary that helps two parties reach an agreement without fighting directly.
"The two neighbors finally resolved their dispute after an elderly woman mediated between them."
acting or brought about through an intervening agency
"the mediated settlement brought satisfaction to both sides"