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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Proving that this is true is difficult because PBH neutrinos would look just like any other neutrinos produced from another source, unless they could be associated with a flash of gamma rays in the sky from an exploding PBH. Quanta Magazine, 23 Jan. 2026 Remarkably, when this envelope finally dispersed, the ejection produced its own blast of gamma rays that NASA’s Fermi was able to observe. Frank Landymore, Futurism, 21 Jan. 2026 The host star emits mostly gamma rays and high-energy particles, which are invisible to Webb’s infrared instruments. Neetika Walter, Interesting Engineering, 16 Dec. 2025 At the same time, the Fermi Space Telescope detected gamma rays from shocks as multiple components in the outflows violently collided. Keith Cooper, Space.com, 11 Dec. 2025 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 30 Jan. 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

More from Merriam-Webster on gamma ray

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