gamma ray

noun

: a photon emitted spontaneously by a radioactive substance
also : a photon of higher energy than that of an X-ray

Examples of gamma ray in a Sentence

Recent Examples on the Web
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Even gamma rays get their day in the sun (so to speak), with the Fermi Gamma-Ray Space Telescope and Swift still operating and producing amazing data. Phil Plait, Scientific American, 15 May 2026 By themselves, these extreme subatomic affairs didn’t seem to be abundant enough to account for the brilliant gamma rays lighting up storm clouds. Quanta Magazine, 6 May 2026 Using this method, the team found that the nebula around PSR J1849-0001 emits gamma rays following a power-law spectrum extending up to 2 PeV—an extreme range rarely seen. Rupendra Brahambhatt, Interesting Engineering, 26 Apr. 2026 Blasts of gamma rays can trap positive charges in the oxide, degrading the device’s performance and causing errors. Katherine Bourzac, IEEE Spectrum, 2 Apr. 2026 See All Example Sentences for gamma ray

Word History

First Known Use

1903, in the meaning defined above

Time Traveler
The first known use of gamma ray was in 1903

Cite this Entry

“Gamma ray.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/gamma%20ray. Accessed 20 May. 2026.

Kids Definition

gamma ray

noun
: a ray that is like an X-ray but of higher energy and that is given off especially by a radioactive substance

Medical Definition

gamma ray

noun
: a photon emitted spontaneously by a radioactive substance
also : a high-energy photon
usually used in plural

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