transistor

American  

[tran-zis-ter] / trænˈzɪs tər /

noun

1. Electronics. a semiconductor device that amplifies, oscillates, or switches the flow of current between two terminals by varying the current or voltage between one of the terminals and a third: although much smaller in size than a vacuum tube, it performs similar functions without requiring current to heat a cathode.

2. Informal. a transistorized radio.

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adjective

1. Informal. transistorized.

   a transistor radio.

transistor British  

/ trænˈzɪstə /

noun

1. a semiconductor device, having three or more terminals attached to electrode regions, in which current flowing between two electrodes is controlled by a voltage or current applied to one or more specified electrodes. The device is capable of amplification, etc, and has replaced the valve in most circuits since it is much smaller, more robust, and works at a much lower voltage See also junction transistor field-effect transistor

2. informal a transistor radio

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transistor Scientific  

/ trăn-zĭs′tər /

1. An electronic device that controls the flow of an electric current, most often used as an amplifier or switch. Transistors usually consist of three layers of semiconductor material, in which the flow of electric current across the outer layer is regulated by the voltage or current applied at the middle layer. Having replaced the vacuum tube, transistors are the basis of much modern electronic technology, including the microprocessor.

2. See also logic circuit logic gate

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transistor Cultural  

1. An electronic device that can work as an amplifier, transforming weak electrical signals into strong ones. It is normally made from silicon or other semiconductors.

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Discover More

The transistor is the basic device used in miniaturized electronic systems, such as portable radios, or as a fast switch in computers.

Etymology

Origin of transistor

First recorded in 1945–50; trans(fer) + (res)istor

Explanation

Use the noun transistor to describe the small metal device that helps send and amplify signals in a radio. Your grandpa might carry a transistor radio around on game day. You may have heard of a transistor radio, or a portable radio that was produced in the 1950s after the development of transistors. These tiny devices made it possible for much smaller electronics to be made, like radios that people could carry in their hands. Transistors are still used in electronic products today. The word comes from the words transfer and resistor, because an electrical current in a transistor is transferred across a resistor, a two-terminal component of electronics.

Example Sentences

The MTS traces its roots back a century to Bell Labs, the iconic research organization that developed technologies such as the transistor, the laser and various programming languages.

From MarketWatch • May 9, 2026

The 1948 invention of the transistor and the 1972 microprocessor led to smaller, more-powerful computers and helped the internet’s rise.

From The Wall Street Journal • Apr. 26, 2026

L.A. literature: In a durably famous metaphor for Southern California, “The Crying of Lot 49’s” heroine, Oedipa, compares the sight of a distant sprawling suburb to a transistor radio’s printed circuit board.

From Los Angeles Times • Apr. 9, 2026

"There was a lot of development between the discovery of a reaction for sequencing DNA and modern genomics; decades between the first transistor and putting a billion transistors on a chip," Chait says.

From Science Daily • Mar. 25, 2026

The bells of the ice-cream truck jangled across the street, and a sudden roar burst from a dozen transistor radios.

From "The Contender" by Robert Lipsyte