ˌan-ˌtī- How to pronounce antiproton (audio)
: the antiparticle of the proton

Example Sentences

Recent Examples on the Web This separation—called the hyperfine split—is caused by interactions between the antiproton and the helium nucleus. John Timmer, Ars Technica, 16 Mar. 2022 At 2pm today, in a field not far from downtown Chicago, a final proton will smash into an antiproton. Daniel Holz, Discover Magazine, 30 Sep. 2011 Carlo Rubbia, who lead UA1, and Simon van der Meer, who designed the antiproton source, shared the Nobel the next year. John Conway, Discover Magazine, 10 Jan. 2011 In contrast, the higher energies used in the ALPHA experiment slow antiprotons and positrons down enough for the particles to form atoms of antihydrogen for more in-depth study. Jonathan O'callaghan, Scientific American, 19 Feb. 2020 Doing so allowed them to observe that in antihydrogen—which is composed of an antiproton and a positron, the electron’s antiparticle—jumps in energy levels known as the Lamb shift were identical to those seen in hydrogen. Jonathan O'callaghan, Scientific American, 19 Feb. 2020 The dance between positron and antiproton in antihydrogen should exactly follow that of the electron and proton in hydrogen. Sophia Chen, Wired, 19 Feb. 2020 To make antihydrogen, the ALPHA team used CERN’s particle colliders and other machines, which produce antiprotons and positrons. Sophia Chen, Wired, 19 Feb. 2020 Hundreds of billions of protons and antiprotons were accelerated close to the speed of light and then smashed together. Quanta Magazine, 7 Aug. 2019 See More

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

Word History

First Known Use

1931, in the meaning defined above

Time Traveler
The first known use of antiproton was in 1931

Dictionary Entries Near antiproton

Cite this Entry

“Antiproton.” Dictionary, Merriam-Webster, Accessed 28 Mar. 2023.

Kids Definition


an·​ti·​pro·​ton ˌant-i-ˈprō-ˌtän How to pronounce antiproton (audio)
: the part of antimatter related to the proton

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