antiparticle

noun

an·​ti·​par·​ti·​cle ˈan-tē-ˌpär-ti-kəl  ˈan-ˌtī- 

: a subatomic particle identical to another subatomic particle in mass but opposite to it in electric and magnetic properties (such as sign of charge) that when brought together with its counterpart produces mutual annihilation

especially : a subatomic particle not found in ordinary matter

Examples of antiparticle in a Sentence

Recent Examples on the Web

Earth’s best vacuum CERN currently has several antimatter experiments underway, each producing a different type of antiparticle. —Jacopo Prisco, CNN Money, 27 Mar. 2026

The trap also maintains an ultrahigh vacuum so that there’s no chance that any regular particles will collide with the antiparticles. —Emma Gometz, Scientific American, 25 Mar. 2026

The difference in what the vacuum state is in different regions of space — particularly in the presence of a horizon, whether a cosmological or an event horizon — leads to the production of radiation and particle-antiparticle pairs wherever quantum fields are present. —Big Think, 24 Mar. 2026

As scientists understand the universe today, for every type particle that exists, there is a corresponding antiparticle, exactly matching the particle but with an opposite charge. —ABC News, 23 Mar. 2026

Word History

First Known Use

1934, in the meaning defined above

Rhymes for antiparticle

• article
• particle
• interparticle
• nanoparticle
• quasiparticle

Kids Definition

antiparticle

noun

an·​ti·​par·​ti·​cle ˈant-i-ˌpärt-i-kəl 

ˈan-ˌtī-

: an elementary particle identical to another elementary particle in mass but opposite to it in electric or magnetic properties