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muon

noun

mu·​on ˈmyü-ˌän How to pronounce muon (audio)
: an unstable lepton that is common in the cosmic radiation near the earth's surface, has a mass about 207 times the mass of the electron, and exists in negative and positive forms
muonic adjective

Examples of muon 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.
Cosmic rays batter Earth's atmosphere constantly, interacting with molecules of air and producing showers of exotic particles such as muons, high energy neutrons and positrons. Tereza Pultarova, Space.com, 3 Dec. 2025 The analysis combined the results from two major long-baseline experiments that send beams of muon neutrinos across hundreds of miles to distant detectors. Georgina Jedikovska, Interesting Engineering, 23 Oct. 2025 Combine that with new predictions by the related Muon g-2 Theory Initiative using a new means of calculating the muon's magnetic moment, and the discrepancy between theoretical prediction and experiment narrows even further. ArsTechnica, 30 June 2025 The heart of the experiment is a giant 50-foot-diameter magnet, which acts as a racetrack for wobbling muons. Eleni Petrakou, Scientific American, 8 June 2025 See All Example Sentences for muon

Word History

Etymology

contraction of earlier mu-meson, from mu

First Known Use

1951, in the meaning defined above

Time Traveler
The first known use of muon was in 1951

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Cite this Entry

“Muon.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/muon. Accessed 10 Dec. 2025.

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