To act as a broker in; to arrange or negotiate.
To act as a broker; to mediate in a sale or transaction.
An agent involved in the exchange of messages or transactions.
A mediator between a buyer and seller.
A stockbroker.
A mediator in general, one who liaises between two or more parties to attempt to achieve an outcome of some kind.
To act as an umpire (in).
An umpire.