What does "antiparticle" mean?

A subatomic particle corresponding to another particle with the same mass, spin and mean lifetime but with charge, parity, strangeness and other quantum numbers flipped in sign; a particle that has a reversed world line to another.

How do you pronounce "antiparticle"?

Pronounced //ˈæntiˌpɑ(ɹ)tɪkəl//.

Antiparticle

//ˈæntiˌpɑ(ɹ)tɪkəl// noun

noun ·Rare ·Advanced level

Definitions

Noun

1
A subatomic particle corresponding to another particle with the same mass, spin and mean lifetime but with charge, parity, strangeness and other quantum numbers flipped in sign; a particle that has a reversed world line to another. particle
"There could be whole antiworlds and antipeople made out of antiparticles. However, if you meet your antiself, don't shake hands!"
2
a particle that has the same mass as another particle but has opposite values for its other properties; interaction of a particle and its antiparticle results in annihilation and the production of radiant energy wordnet

Example

More examples

"A photon is its own antiparticle."

Etymology

From anti- + particle.

More for "antiparticle"

Synonyms Sentences Pronunciation Translate

Next best steps

Find stronger synonyms See usage examples Check pronunciation Browse writing guides

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.