Dictionary.com Unabridged (v 1.1) - Cite This Source - Share This

American Heritage Dictionary - Cite This Source - Share This

con·duc·tor       (kən-dŭk'tər)  Pronunciation Key  n.   One who conducts, especially: One who is in charge of a railroad train, bus, or streetcar. Music One who directs an orchestra or other such group. Physics A substance or medium that conducts heat, light, sound, or especially an electric charge. A lightning rod, as on a house or barn. con'duc·to'ri·al (kŏn'dŭk-tôr'ē-əl, -tōr'-) adj., con·duc'tor·ship' n.

WordNet - Cite This Source - Share This

conductor
noun
1.	the person who leads a musical group
2.	a substance that readily conducts e.g. electricity and heat [ant: dielectric]
3.	the person who collects fares on a public conveyance
4.	a device designed to transmit electricity, heat, etc.

The American Heritage Science Dictionary - Cite This Source - Share This

conductor       (kən-dŭk'tər)  Pronunciation Key  A material or an object that conducts heat, electricity, light, or sound. Electrical conductors contain electric charges (usually electrons) that are relatively free to move through the material; a voltage applied across the conductor therefore creates an electric current. Insulators (electrical nonconductors) contain no charges that move when subject to a voltage. Compare insulator. See also resistance, superconductivity.

American Heritage New Dictionary of Cultural Literacy, Third Edition - Cite This Source - Share This
conductor

A material through which electric current can pass. In general, metals are good conductors. Copper or aluminum is normally used to conduct electricity in commercial and household systems. (Compare insulator.)

American Heritage Stedman's Medical Dictionary - Cite This Source - Share This

conductor con·duc·tor (kən-dŭk'tər)
n.

1. A substance or medium that conducts heat, light, sound, or especially an electric charge.
2. An instrument or probe having a groove along which a knife is passed in slitting open a sinus or fistula; a grooved director.

Webster's Revised Unabridged Dictionary - Cite This Source - Share This

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.