ˈan-ˌtī- How to pronounce antimatter (audio)
: matter composed of antiparticles

Examples of antimatter in a Sentence

Recent Examples on the Web Looking at a list of energy densities, the only thing that could work is some type of nuclear battery or an antimatter source. Rhett Allain, WIRED, 4 May 2024 Theorists can engineer scenarios where new particles and forces explain both the muons’ funny wobbling and solve other outstanding mysteries, such as the nature of dark matter or, even more daring, why matter dominates over antimatter. Marcela Carena, Scientific American, 1 Oct. 2021 But some physicists pondered whether antimatter might instead be repulsed by gravity. Jennifer Ouellette, Ars Technica, 27 Sep. 2023 That there was enough leftover matter after this great annihilation to form galaxies, stars, planets and even us but almost no antimatter is known as the matter-antimatter imbalance. Luke Caldwell, Scientific American, 16 Jan. 2024 Even that tiny imbalance was sufficient to wipe out all of the antimatter in the universe in about one second. Jennifer Ouellette, Ars Technica, 27 Sep. 2023 Some of them seek to offer matter the upper hand by introducing new particles that decay, producing more matter than antimatter in the process, or that interact differently with matter and antimatter. Luke Caldwell, Scientific American, 16 Jan. 2024 When antimatter meets matter, both particles are annihilated and their combined masses are converted into pure energy. Jennifer Ouellette, Ars Technica, 27 Sep. 2023 In other words, does an antimatter droplet fall down or up? Rahul Rao, Popular Science, 27 Sep. 2023

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'antimatter.' 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 antimatter was in 1934

Dictionary Entries Near antimatter

Cite this Entry

“Antimatter.” Dictionary, Merriam-Webster, Accessed 22 Jun. 2024.

Kids Definition


an·​ti·​mat·​ter ˈant-i-ˌmat-ər How to pronounce antimatter (audio)
: matter whose parts match parts of ordinary matter except in having some opposite properties (as a positive instead of a negative charge)

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