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
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.
These pairs are expected to scatter off the cosmic microwave background and then to produce lower-energy gamma rays in the GeV range. Mrigakshi Dixit, Interesting Engineering, 4 Nov. 2025 This phenomenon can be observed in the atmosphere in response to high energy particles (e.g., gamma rays), although it is influenced by both particle energies and atmospheric density. Hannah Millington, MSNBC Newsweek, 28 Oct. 2025 People had previously predicted that finding these genes would be impossible because aging was thought to have multiple causes: oxidative stress, gamma rays, gravity. Dominique Mosbergen, Time, 16 Oct. 2025 Over the years, many scientists have suggested that prospecting for He-3 could be accomplished using high-energy gamma rays, in the 20 megaelectron volt (MeV) region. Leonard David, Space.com, 30 Sep. 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 10 Nov. 2025.

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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