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

There are all sorts of important symmetries, but if everything were completely symmetric, there would have been perfectly equal amounts of matter and antimatter. —Big Think, 27 Nov. 2025

In this process, a top quark and its antimatter counterpart, an anti-top quark, are produced along with a Z boson. —Georgina Jedikovska, Interesting Engineering, 4 Nov. 2025

For example, the matter proton particle is partnered by the antimatter antiproton, while the matter electron is partnered by the antimatter positron. —William Barter, Space.com, 1 Aug. 2025

The feat is exciting, however, because of what such antimatter experiments could reveal about the universe itself. —Clara Moskowitz, Scientific American, 28 July 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)