Geiger counter

noun

Gei·​ger counter ˈgī-gər- How to pronounce Geiger counter (audio)
: an instrument for detecting the presence and intensity of radiations (such as cosmic rays or particles from a radioactive substance) by means of their ionizing effect on an enclosed gas which results in a pulse that is amplified and fed to a device giving a visible or audible indication

Examples of Geiger counter in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Players had to get within a few feet for detection, and a Geiger counter cost far more than a box of new balls. — Christopher McFadden, Interesting Engineering, 28 Oct. 2025 Our Geiger counter, which took live measurements of the environment, clicked quietly. — Lizzie Johnson, New Yorker, 25 Apr. 2026 There, Knight and Torres find empty hazardous material containers, a very busy Geiger counter, and the melty remains of a man who was injected with a radioactive substance. — Sara Netzley, EW.com, 6 May 2025 Dunthorne buys a Geiger counter off the internet and goes to the German town of Oranienburg, the original site of the chemicals lab where Siegfried started work on mustard gas and its antidotes. — Emma Brockes, New York Times, 4 Apr. 2025 See All Example Sentences for Geiger counter

Word History

Etymology

Hans Geiger †1945 German physicist

First Known Use

1924, in the meaning defined above

Time Traveler
The first known use of Geiger counter was in 1924

Rhymes for Geiger counter

See All Rhymes for Geiger counter

Browse Nearby Words

Geiger
Geiger counter
Geiger-Müller counter
See all Nearby Words

Cite this Entry

“Geiger counter.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/Geiger%20counter. Accessed 7 Jul. 2026.

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Kids Definition

Geiger counter

noun
Gei·​ger counter ˌgī-gər- How to pronounce Geiger counter (audio)
: an instrument for detecting the presence of cosmic rays or radioactive substances

Medical Definition

Geiger counter

noun
Gei·​ger count·​er ˈgī-gər-ˌkau̇n-tər How to pronounce Geiger counter (audio)
: an instrument for detecting the presence and intensity of radiations (as cosmic rays or particles from a radioactive substance) by means of the ionizing effect on an enclosed gas which results in a pulse that is amplified and fed to a device giving a visible or audible indication
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