In International law . A public oflicer, clothed with high diplomatic powers, commissioned by a sovereign prince or state to transact the international business of his government at the court, of the country to which he is sent. Ambassador Is the commissioner who represents one country in the seat of government of another. He is a public minister, which, usually, a consul is not. Brown. Ambassador is a person sent by one sovereign to another, with authority, by letters of credence, to treat on affairs of state. Jacob.