antimatter

American  

[an-tee-mat-er, an-tahy-] / ˈæn tiˌmæt ər, ˈæn taɪ- /

noun

Physics.

1. matter composed only of antiparticles, especially antiprotons, antineutrons, and positrons.

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antimatter British  

/ ˈæntɪˌmætə /

noun

1. a form of matter composed of antiparticles, such as antihydrogen, consisting of antiprotons and positrons

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antimatter Scientific  

/ ăn′tĭ-măt′ər /

1. A form of matter that consists of antiparticles.

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antimatter Cultural  

1. In physics, matter made of antiparticles.

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Etymology

Origin of antimatter

First recorded in 1950–55; anti- + matter

Explanation

Antimatter is composed of antiparticles, which have the opposite charge of regular particles. Antimatter is also called negative matter. Matter makes up all the things that exist: everything in the world is matter. Words beginning with anti are opposed to their root. Therefore, antimatter is the opposite of matter. If antimatter and matter were to collide, both would be destroyed, releasing a huge and dangerous amount of energy. This happens because the particles that make up matter and the antiparticles that make up antimatter have opposite electric charges. The existence of antimatter is something studied by physicists.

Example Sentences

Antimatter, on the other hand, is regular matter's twin, though with some opposite properties.

From Science Daily • Sep. 27, 2023

Antimatter would spread as thinly as possible between the galaxies and act like dark energy.

From Science Magazine • Sep. 27, 2023

Antimatter is the opposite of matter, from which stars and planets are made.

From BBC • Sep. 27, 2023

Antimatter, like matter, has mass and takes up space.

From Scientific American • Jul. 28, 2023

Antimatter annihilates with normal matter, producing pure energy.

From Textbooks • Aug. 12, 2015