one who, or that which, conducts; a leader; a commander; a guide; a manager; a director.-one in charge of a public conveyance, as of a railroad train or a street car.-the leader or director of an orchestra or chorus.-a substance or body capable of being a medium for the transmission of certain forces, esp. heat or electricity; specifically, a lightning rod.-a grooved sound or staff used for directing instruments, as lithontriptic forceps, etc.; a director.-same as leader.