any of a group of elementary particles that have the same mass and spin as their corresponding particle but have opposite values for all other nonzero quantum numbers. When a particle collides with its antiparticle, mutual annihilation occurs
WordReference Random House Learner's Dictionary of American English © 2025
an•ti•par•ti•cle /ˈæntiˌpɑrtɪkəl, ˈæntaɪ-/USA pronunciation
n. [countable]
WordReference Random House Unabridged Dictionary of American English © 2025- Physicsan atomic particle whose properties are identical in size to those of a specific elementary particle but are of opposite sign.
an•ti•par•ti•cle
(an′tē pär′ti kəl, an′tī-),USA pronunciation n. [Physics.]
- Physicsa particle all of whose properties, as mass, spin, or charge, have the same magnitude as but, where appropriate, the opposite sign of a specific elementary particle;
neutral pions, photons, and gravitons are considered to be their own antiparticles:The positron is the antiparticle of the electron.Cf. antimatter, annihilation (def. 3).
- anti- + particle 1930–35
Collins Concise English Dictionary © HarperCollins Publishers::
'antiparticle' also found in these entries (note: many are not synonyms or translations):
annihilation
- anti
- anti-
- antibaryon
- antilepton
- antimuon
- antineutrino
- antineutron
- antiproton
- antiquark
- charge conjugation
- eta meson
- graviton
- kaon
- muon
- pair production
- photon
- positron
- tauon