Definition of "conductor" []

• One who conducts, especially: (noun)
• One who is in charge of a railroad train, bus, or streetcar. (noun)
• Music One who directs an orchestra or other such group. (noun)
• Physics A substance or medium that conducts heat, light, sound, or especially an electric charge. (noun)
• A lightning rod, as on a house or barn. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "The conductor not indicating anything during this period (rendered somewhat considerable by the extreme slowness of the movement), the players are then entirely left to themselves, _without conductor_; and as the rhythmical feeling is not the same with all, it follows that some hurry, while others slacken, and unity is soon destroyed."
• "The effects to be considered _depend on the conductor_ employed to complete the communication between the zinc and copper plates of the electromotor; and I shall have to consider this conductor under four different forms: as the helix of an electro-magnet (1056); as an ordinary helix (1053, &c.); as a _long_ extended wire, having its course such that the parts can exert little or no mutual influence; and as a _short_ wire."
• "The orchestra conductor is a violinist who has conducted in both the United States and China."