intermediary(an agent acting as a mediator between sides to facilitate agreement or cooperation, see also: mediator) noun [UK: ˌɪn.tə.ˈmiː.dɪə.ri] [US: ˌɪn.tər.ˈmiː.die.ri]
mediator [mediators](one who negotiates between parties seeking mutual agreement) noun [UK: ˈmiː.dɪeɪ.tə(r)] [US: ˈmiː.di.ˌe.tər]