positron

noun

pos·​i·​tron ˈpä-zə-ˌträn How to pronounce positron (audio)
: a positively charged particle having the same mass and magnitude of charge as the electron and constituting the antiparticle of the electron

called also antielectron

Examples of positron 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.
Pending a final decision by the CERN Council in 2028, construction of the initial electron-positron phase (FCC-ee) is slated to begin in 2030, with operations likely to launch in 2047. Mrigakshi Dixit, Interesting Engineering, 20 Jan. 2026 Antiprotons and positrons make up antimatter atoms, or anti-atoms. Dipangkar Dutta, The Conversation, 15 Dec. 2025 Hospitals with radiation-emitting equipment, such as positron emission tomography scanners, sometimes release radioactive gases into the atmosphere. Chris Baraniuk, Wired News, 15 Dec. 2025 Cosmic rays batter Earth's atmosphere constantly, interacting with molecules of air and producing showers of exotic particles such as muons, high energy neutrons and positrons. Tereza Pultarova, Space.com, 3 Dec. 2025 See All Example Sentences for positron

Word History

Etymology

positive + -tron (as in electron)

First Known Use

1933, in the meaning defined above

Time Traveler
The first known use of positron was in 1933

Cite this Entry

“Positron.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/positron. Accessed 31 Jan. 2026.

Kids Definition

positron

noun
pos·​i·​tron ˈpäz-ə-ˌträn How to pronounce positron (audio)
: a positively charged particle having the same mass and size of charge as the electron

Medical Definition

positron

noun
pos·​i·​tron ˈpäz-ə-ˌträn How to pronounce positron (audio)
: a positively charged particle having the same mass and magnitude of charge as the electron and constituting the antiparticle of the electron

called also positive electron

More from Merriam-Webster on positron

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