positronium

noun

pos·​i·​tro·​ni·​um ˌpä-zə-ˈtrō-nē-əm How to pronounce positronium (audio)
: a short-lived system that consists of a positron and an electron bound together and is suggestive of a hydrogen atom

Examples of positronium 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.
For example, in the 1990s physicists thought, essentially, that positronium didn’t live as long as predicted. Adrian Cho, Science | AAAS, 25 Aug. 2020 That makes positronium an ideal tool with which to look for new physics, Cassidy says. Adrian Cho, Science | AAAS, 25 Aug. 2020

Word History

First Known Use

1945, in the meaning defined above

Time Traveler
The first known use of positronium was in 1945

Cite this Entry

“Positronium.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/positronium. Accessed 13 Mar. 2025.

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