noun ·Rare ·Advanced level

Definitions

Noun

1. 1
   An unstable elementary particle which is a type of lepton, having a mass almost twice that of a proton, a negative charge, and a spin of ½; it decays into hadrons (usually pions) or other leptons, and neutrinos.
2. 2
   a lepton of very great mass wordnet

Synonyms

All synonyms

tautau leptontau leptontau minus particletau particletau-minus particle

Etymology

From tau + -on, tau short for Ancient Greek τρίτος (trítos, “third”), being the third lepton discovered.

Related phrases

elementary particletau neutrino

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