ax·​ion ˈak-sē-(ˌ)än How to pronounce axion (audio)
: a hypothetical subatomic particle of low mass and energy that is postulated to exist because of certain properties of the strong force

Examples of axion in a Sentence

Recent Examples on the Web Fuzzy dark matter axions would be even lighter than this. Robert Lea, Popular Mechanics, 3 Aug. 2023 If an oscillating axion field matched this frequency, an axion could be converted into microwave radiation with that same frequency. Rachel Courtland, IEEE Spectrum, 1 May 2014 Because only a small number of those photons would match the axion frequency, few would trigger an axion conversion. Rachel Courtland, IEEE Spectrum, 1 May 2014 Thus, Hertzberg was already quite familiar with axions. Chanda Prescod-Weinstein, Scientific American, 1 Apr. 2022 But axions may be making a comeback, or at least holding steady while WIMPs faceplant. John Timmer, Ars Technica, 21 Apr. 2023 So, what's an axion? John Timmer, Ars Technica, 21 Apr. 2023 What’s an axion? Caroline Delbert, Popular Mechanics, 17 June 2020 Alternatively, dark matter may consist of some possible elementary particles known as QCD axions that are extremely lightweight. Kat Friedrich, Popular Mechanics, 10 Mar. 2023 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'axion.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


axi(al) + -on entry 2

Note: The name axion was introduced by the American physicist Stephen Weinberg (born 1933) in "A New Light Boson?", Physical Review Letters, vol. 40, no. 4 (January 23, 1978), p. 233; and by American physicist Frank Wilczek (born 1951) in "Problems of Strong P and T Invariance in the Presence of Instantons," Physical Review Letters, vol. 40, no. 5, p. 279. In an article in the online journal Quanta, "Time's (Almost) Irreversible Arrow" (January 7, 2016), Frank Wilczek explained the coinage as follows: "A few years before [in 1977], a supermarket display of brightly colored boxes of a laundry detergent named Axion had caught my eye. It occurred to me that 'axion' sounded like the name of a particle and really ought to be one. So when I noticed a new particle that 'cleaned up' a problem with an 'axial' current, I saw my chance. (I soon learned that Steven Weinberg had also noticed this particle, independently. He had been calling it the 'Higglet.' He graciously, and I think wisely, agreed to abandon that name.) Thus began a saga whose conclusion remains to be written."

First Known Use

1978, in the meaning defined above

Time Traveler
The first known use of axion was in 1978

Dictionary Entries Near axion

Cite this Entry

“Axion.” Dictionary, Merriam-Webster, Accessed 9 Dec. 2023.

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