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.

Zeal, the blind conductor of the will. --Dryden.

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

3. (Mus.) The leader or director of an orchestra or chorus.

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.

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

6. (Arch.) Same as Leader.

Prime conductor (Elec.), the largest conductor of an electrical machine, serving to collect, accumulate, or retain the electricity.

Source: Webster's Revised Unabridged Dictionary (1913)