Prime conductor

Conductor Con*duct"or (k[o^]n*d[u^]k"t[~e]r), n. [LL., a carrier, transporter, L., a lessee.] 1. One who, or that which, conducts; a leader; a commander; a guide; a manager; a director. [1913 Webster]

Zeal, the blind conductor of the will. --Dryden. [1913 Webster]

2. One in charge of a public conveyance, as of a railroad train or a street car. [U. S.] [1913 Webster]

3. (Mus.) The leader or director of an orchestra or chorus. [1913 Webster]

4. (Physics) A substance or body capable of being a medium for the transmission of certain forces, esp. heat or electricity; specifically, a lightning rod. [1913 Webster]

5. (Surg.) A grooved sound or staff used for directing instruments, as lithontriptic forceps, etc.; a director. [1913 Webster]

6. (Arch.) Same as {Leader}. [1913 Webster]

{Prime conductor} (Elec.), the largest conductor of an electrical machine, serving to collect, accumulate, or retain the electricity. [1913 Webster]