1. A slender flexible rod, stick, or twig, especially one used for whipping.
2. The bushy tip of the tail of certain animals: a cow's switch.
3. A thick strand of real or synthetic hair used as part of a coiffure.
4. A flailing or lashing, as with a slender rod.
5. A device used to break or open an electric circuit or to divert current from one conductor to another.
6. A device consisting of two sections of railroad track and accompanying apparatus used to transfer rolling stock from one track to another.
7. 1. The act or process of operating a switching device.
   2. The result achieved by such an act.
8. An exchange or a swap, especially one done secretly.
9. A transference or shift, as of opinion or attention.

1. Chiefly Southern U.S. To whip with or as if with a switch, especially in punishing a child.
2. To jerk or swish abruptly or sharply: a cat switching its tail.
3. To shift, transfer, or divert: switched the conversation to a lighter subject.
4. To exchange: asked her brother to switch seats with her.
5. To connect, disconnect, or divert (an electric current) by operating a switch.
6. To cause (an electric current or appliance) to begin or cease operation: switched the lights on and off.
7. Informal. To produce as if by operating a control. Often used with on: switched on the charm.
8. To move (rolling stock) from one track to another; shunt.

1. To make or undergo a shift or an exchange: The office has switched to shorter summer hours.
2. To swish sharply from side to side.

switch off Informal.

1. To stop paying attention; lose interest.

[Probably of Low German or Flemish origin.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.