broker

Short definition from Wiktionary

Adjective

1. 1
   comparative form of broke: more broke

Noun

1. 1
   A mediator between a buyer and seller.
2. 2
   A stockbroker.
3. 3
   A mediator in general, one who liaises between two or more parties to attempt to achieve an outcome of some kind.
4. 4
   An agent involved in the exchange of messages or transactions.

Verb

1. 1
   To act as a broker; to mediate in a sale or transaction.
2. 2
   To act as a broker in; to bring about through brokering or negotiation; to arrange or negotiate.

Proper noun

1. 1
   A surname.