intermediator(n = noun.person) go-between, intercessor, intermediary, mediator - a negotiator who acts as a link between parties;
is a kind of negotiant, negotiator, treater
has particulars: mediatrix, conciliator, make-peace, pacifier, peacemaker, reconciler, diplomat, harmoniser, harmonizer, interpreter, translator, marriage broker, matcher, matchmaker, moderator, second hand
Derived form verb intermediate₁

   A mediator. [1913 Webster]