Switch

a slender, flexible shoot, rod, etc., used especially in whipping or disciplining.
an act of whipping or beating with or as with such an object; a stroke, lash, or whisking movement.
a slender growing shoot, as of a plant.
a hairpiece consisting of a bunch or tress of long hair or some substitute, fastened together at one end and worn by women to supplement their own hair.
Electricity. a device for turning on or off or directing an electric current or for making or breaking a circuit.
Railroads. a track structure for diverting moving trains or rolling stock from one track to another, commonly consisting of a pair of movable rails.
a turning, shifting, or changing:
a switch of votes to another candidate.
Bridge. a change to a suit other than the one played or bid previously.
Basketball. a maneuver in which two teammates on defense shift assignments so that each guards the opponent usually guarded by the other.
a tuft of hair at the end of the tail of some animals, as of the cow or lion.
to whip or beat with a switch or the like; lash:
He switched the boy with a cane.
to move, swing, or whisk (a cane, a fishing line, etc.) with a swift, lashing stroke.
to shift or exchange:
The two girls switched their lunch boxes.
to turn, shift, or divert:
to switch conversation from a painful subject.
Electricity. to connect, disconnect, or redirect (an electric circuit or the device it serves) by operating a switch (often followed by off or on):
I switched on a light.
Railroads.

to move or transfer (a train, car, etc.) from one set of tracks to another.
to drop or add (cars) or to make up (a train).

Movies, Television. to shift rapidly from one camera to another in order to change camera angles or shots.
to strike with or as with a switch.
to change direction or course; turn, shift, or change.
to exchange or replace something with another:
He used to smoke this brand of cigarettes, but he switched.
to move or sway back and forth, as a cat’s tail.
to be shifted, turned, etc., by means of a switch.
Basketball. to execute a switch.
Bridge. to lead a card of a suit different from the suit just led by oneself or one’s partner.
asleep at the switch, Informal. failing to perform one’s duty, missing an opportunity, etc., because of negligence or inattention:
He lost the contract because he was asleep at the switch.
Contemporary Examples

The tripwire for an unfolding plot to take control of the flight would be the transponder, operated by a switch beside the pilots.
Who Gagged the Search for MH370? Clive Irving June 21, 2014

College radio is everywhere, so I could hear both Vampire Weekend and NPR at the flip of a switch.
Prisoners Get Cultural Fix with 8-Tracks and Bootleg Cassettes Daniel Genis August 17, 2014

Without its Korean frenemy, the company will have to switch to a new megasupplier.
Here’s Why Apple and Samsung Are Breaking Up Alex Klein December 30, 2012

She said she had made the switch for a movie role — though she wouldn’t say which one.
Natalie Portman Goes Blonde; Valentino To Design Hathaway’s Wedding Dress The Fashion Beast Team September 23, 2012

On the final day of the campaign, a dreary New England day, the two candidates seemed to switch strategies.
Massachusetts Miracle Samuel P. Jacobs January 18, 2010

Historical Examples

Their master was walking among them with a pipe in his mouth, and a switch in his hand.
Paul and Virginia Bernardin de Saint Pierre

He depressed the switch deliberately, like a man firing a weapon.
Final Weapon Everett B. Cole

The circuit is completed by turning a switch and the plating begins.
The Wonder Book of Knowledge Various

The knob is the switch and intensity control, and it’s quite sensitive.
Final Weapon Everett B. Cole

Dr. Bird stumbled to the switch and closed it, and the ball was flooded with light.
Astounding Stories of Super-Science, December 1930 Various

noun
a mechanical, electrical, electronic, or optical device for opening or closing a circuit or for diverting energy from one part of a circuit to another
a swift and usually sudden shift or change
an exchange or swap
a flexible rod or twig, used esp for punishment
the sharp movement or blow of such an instrument
a tress of false hair used to give added length or bulk to a woman’s own hairstyle
the tassel-like tip of the tail of cattle and certain other animals
any of various card games in which the suit is changed during play
(US & Canadian) a railway siding
(US & Canadian) a railway point
(Austral, informal) See switchboard
verb
to shift, change, turn aside, or change the direction of (something)
to exchange (places); replace (something by something else): the battalions switched fronts
(mainly US & Canadian) to transfer (rolling stock) from one railway track to another
(transitive) to cause (an electric current) to start or stop flowing or to change its path by operating a switch
to swing or cause to swing, esp back and forth
(transitive) to lash or whip with or as if with a switch
n.

1590s, “slender riding whip,” probably from a Flemish or Low German word akin to Hanoverian swutsche, a variant of Low German zwukse “long thin stick, switch,” from Germanic base *swih- (cf. Old High German zwec “wooden peg,” German Zweck “aim, design,” originally “peg as a target,” Zwick “wooden peg”), perhaps connected with PIE root *swei- “to swing, bend, to turn.”

The meaning “device for changing the direction of something or making or breaking a connection” is first recorded 1797. “The peg sense suits the mech(anical) applications” [Weekley], and these senses may be a direct borrowing from those senses in Continental Germanic languages rather than a continuation of the “pliant wand” sense. The meaning “a change, a reversal, an exchange, a substitution” is first recorded 1920.
v.

1610s, “to strike with a switch,” from switch (n.). Related: Switched; switching. The meaning “turn off or on” is first recorded 1853 of trains on tracks, 1881 of electricity, 1932 of radio or (later) television. Sense of “shift, divert” is from 1860. Meaning “to change one thing for another” is recorded from 1919. Switch-hitter is 1930s in baseball slang, 1956 in the sense of “bisexual person.”

noun

A change, esp a reversal or major alteration: This is a big switch for the reigning party (1920+)
An exchange, esp an illicit substitution: He made a switch, giving her the empty purse and taking the valuable one (1935+)

verb

To inform; snitch (1940s+ Underworld)

Related Terms

asleep at the switch, chicken switch, not have all one’s switches on

1. switch statement.
2. command line option.
3. packet switch, circuit switch.
(1999-01-14)

switch off
switch on

also see:

asleep at the switch
bait and switch