emitter

American

[ih-mit-er] / ɪˈmɪt ər /

noun

a person or thing that emits.
Electronics. an electrode on a transistor from which a flow of electrons or holes enters the region between the electrodes.

emitter British

/ ɪˈmɪtə /

noun

a person or thing that emits
a radioactive substance that emits radiation

a beta emitter
the region in a transistor in which the charge-carrying holes or electrons originate

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of emitter

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

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

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

India is the world's most populous country, the third-biggest emitter of greenhouse gases, and remains deeply dependent on polluting coal to meet soaring energy demand.

From Barron's • Nov. 5, 2025

China, the world's biggest emitter of planet-warming gases, is expected to send a delegation, but President Xi Jinping is not likely to be there.

From BBC • Oct. 30, 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

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023