ˈan-ˌtī- How to pronounce antiparticle (audio)
: a subatomic particle identical to another subatomic particle in mass but opposite to it in electric and magnetic properties (such as sign of charge) that when brought together with its counterpart produces mutual annihilation
especially : a subatomic particle not found in ordinary matter

Examples of antiparticle in a Sentence

Recent Examples on the Web An article on Thursday about antimatter referred incorrectly to some attributes of antiparticles. New York Times, 2 Oct. 2023 If dark matter particles are also their own antiparticles, as many dark matter theories posit, then within these collapsing clouds, those particles would have collided with each other and self-annihilated. Stephanie Pappas, Scientific American, 20 July 2023 Hawking wanted to know what would happen to pairs of particles—a particle and its antiparticle partner—that spontaneously appeared at a black hole’s event horizon. Adam Mann, Scientific American, 22 June 2023 Luckily for us, particles outnumber antiparticles by a significant amount. Jackie Appel, Popular Mechanics, 7 June 2023 If there were an equal number of particles and antiparticles, nothing would exist. Jackie Appel, Popular Mechanics, 7 June 2023 This is created when pairs of particles and their antiparticles quickly pop into and out of existence, which happens pretty much everywhere all the time. Briley Lewis, Popular Science, 20 Mar. 2023 Specifically, Vorobyev’s team zeroed in on a version of the antiparticle known as antihelium-3, composed of two antiprotons and one antineutron. Sophia Chen, WIRED, 14 Dec. 2022 And whereas other particles have an antimatter twin — identical in mass but opposite in charge — Majorana fermions are, technically, their own antiparticle. Devin Powell, Discover Magazine, 20 Mar. 2019 See More

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

Word History

First Known Use

1934, in the meaning defined above

Time Traveler
The first known use of antiparticle was in 1934

Dictionary Entries Near antiparticle

Cite this Entry

“Antiparticle.” Dictionary, Merriam-Webster, Accessed 30 Nov. 2023.

Kids Definition


an·​ti·​par·​ti·​cle ˈant-i-ˌpärt-i-kəl How to pronounce antiparticle (audio)
: an elementary particle identical to another elementary particle in mass but opposite to it in electric or magnetic properties

More from Merriam-Webster on antiparticle

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