antimatter

noun

an·​ti·​mat·​ter

ˈan-tē-ˌma-tər,

ˈan-ˌtī- 

: matter composed of antiparticles

Examples of antimatter in a Sentence

Recent Examples on the Web

Small amounts of antimatter are also produced by lightning during a thunderstorm but they are almost instantly annihilated by matter, Vaudo notes. —Bruce Dorminey, Forbes.com, 23 Apr. 2025

In the beginning, the Universe was very dense and hot, and particles of matter and antimatter interacted, annihilating each other, notes Vaudo. —Bruce Dorminey, Forbes.com, 23 Apr. 2025

Such violation has already been observed in quarks (another building block of the universe), but that discrepancy wasn’t enough to account for the preponderance of matter over antimatter. —Discover Magazine, 26 Mar. 2025

This may sound very strange as it is connected to pairs of matter and antimatter particles popping in and out of existence. —Robert Lea, Space.com, 27 Mar. 2025

Word History

First Known Use

1934, in the meaning defined above

Rhymes for antimatter

• atter
• batter
• blatter
• catarrh
• chatter
• clatter
• fatter
• flatter
• hatter
• latter
• matter
• natter

Kids Definition

antimatter

noun

an·​ti·​mat·​ter ˈant-i-ˌmat-ər 

: matter whose parts match parts of ordinary matter except in having some opposite properties (as a positive instead of a negative charge)