antimatter

noun

an·​ti·​mat·​ter ˈan-tē-ˌma-tər How to pronounce antimatter (audio) ˈan-ˌtī- How to pronounce antimatter (audio)
: matter composed of antiparticles

Examples of antimatter in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
This is akin to what happens when an electron meets its antimatter counterpart, or positron. — Robert Lea, Space.com, 21 June 2026 Last year two teams independently published real-time quantum simulations of the creation of matter and antimatter during a process called string breaking. — Zeeya Merali, Scientific American, 19 May 2026 Matter is so dominant in our universe that any antimatter typically encounters matter quickly and annihilates. — Quanta Magazine, 15 June 2026 Recently, the SpaceX founder and CEO shared a new prediction about antimatter propulsion on the social media platform X and received overwhelming support. — Ameya Paleja, Interesting Engineering, 23 June 2026 See All Example Sentences for antimatter

Word History

First Known Use

1934, in the meaning defined above

Time Traveler
The first known use of antimatter was in 1934

Rhymes for antimatter

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Browse Nearby Words

anti-materialism
antimatter
antimechanized
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Cite this Entry

“Antimatter.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/antimatter. Accessed 7 Jul. 2026.

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Kids Definition

antimatter

noun
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)

More from Merriam-Webster on antimatter

Britannica.com: Encyclopedia article about antimatter

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