lepton

noun

1. 1.A coin used since ancient times in Greece, serving in modern times as one hundredth of a phoenix, a drachma, and a euro (as the Greek form of the Eurocent).
2. 2.A small, bronze Judean coin from the 1st century B.C.E., considered by some to be the widow's mite.
3. 3.An elementary particle that has a spin of 1/2 (i.e., is a fermion) and does not interact via the strong nuclear force; examples include the electron, the muon, the neutrino and the tauon.