: 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
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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
Dictionary Entries Near antiparticle
Cite this Entry
“Antiparticle.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/antiparticle. Accessed 30 Nov. 2023.
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Kids Definition
antiparticle
noun
an·ti·par·ti·cle
ˈant-i-ˌpärt-i-kəl 
ˈan-ˌtī-
: 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
Britannica.com: Encyclopedia article about antiparticle
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