emitter

American  

[ih-mit-er] / ɪˈmɪt ər /

noun

1. a person or thing that emits.

2. Electronics. an electrode on a transistor from which a flow of electrons or holes enters the region between the electrodes.

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emitter British  

/ ɪˈmɪtə /

noun

1. a person or thing that emits

2. a radioactive substance that emits radiation

   a beta emitter

3. the region in a transistor in which the charge-carrying holes or electrons originate

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Etymology

Origin of emitter

First recorded in 1880–85; emit + -er ¹

Example Sentences

They identified a molybdenum-based "spin-flip" emitter as an effective solution.

From Science Daily • Mar. 28, 2026

By placing the sample extremely close to the emitter, the team captured the terahertz light before it could spread out.

From Science Daily • Mar. 17, 2026

China is the world's biggest emitter of the gases that drive climate change, and has committed to peaking emissions by 2030, though some analysts expect it will do so early.

From Barron's • Feb. 12, 2026

Meanwhile, if global shipping were a country, it would reportedly be the sixth-largest greenhouse-gas emitter in the world.

From The Wall Street Journal • Oct. 20, 2025

Their method involved bombarding aluminum foils with alpha rays produced by their usual rudimentary source, a hunk of the inexpensive but vigorous alpha emitter polonium.

From "Big Science" by Michael Hiltzik