switch 
(swĭch)
(swĭch)n.
1.
a. An exchange or a swap, especially one done secretly.
b. A transference or shift, as of opinion or attention.
2.
a. A device used to break or open an electric circuit or to divert current from one conductor to another.
b. A device consisting of two sections of railroad track and accompanying apparatus used to transfer rolling stock from one track to another.
3.
a. A slender flexible rod, stick, or twig, especially one used for whipping.
b. The bushy tip of the tail of certain animals: a cow's switch.
c. A thick strand of real or synthetic hair used as part of a coiffure.
d. A flailing or lashing, as with a slender rod: gave the ox a switch.
v. switched, switch·ing, switch·es
v.tr.
1.
a. To exchange: asked her brother to switch seats with her.
b. To shift, transfer, or divert: switched the conversation to a lighter subject.
2.
a. To connect, disconnect, or divert (an electric current) by operating a switch.
b. To cause (an electric current or appliance) to begin or cease operation: switched the lights on and off.
c. Informal To produce as if by operating a control. Often used with on: switched on the charm.
3. To move (rolling stock) from one track to another; shunt.
4.
a. To whip with a switch, especially in punishing a child.
b. To jerk or swish abruptly or sharply: a cat switching its tail.
v.intr.
Phrasal Verb: 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
To stop paying attention; lose interest.
[Probably of Low German or Flemish origin.]
switcha·ble adj.
switcher n.