ax·​ion | \ ˈak-sē-(ˌ)än How to pronounce axion (audio) \

Definition of axion

: 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

The hunt for wispy particles called axions, which might make up the dark matter whose gravity keeps galaxies from falling apart, is heating up. Adrian Cho, Science | AAAS, "Search for superlight dark matter particles heats up," 9 Apr. 2018 Or hypothesized particles called axions that interact with magnetic fields might be detected in laboratories or in space. Lisa Randall, Scientific American, "What Is Dark Matter?," 8 May 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'axion.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of axion

1978, in the meaning defined above

History and Etymology for axion

axial + -on entry 2

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The first known use of axion was in 1978

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