Origin: ME taw, tau (esp. with ref. to the tau cross) < L tau < Gr < Sem, as in Heb tav, tav
Used by arrangement with John Wiley & Sons, Inc.
- The 19th letter of the Greek alphabet. See Table at alphabet.
- An elementary particle of the lepton family, having a mass about 3,550 times that of the electron, a negative electric charge, and a mean lifetime of 3 × 10-13 seconds. See Table at subatomic particle.
Origin: Greek, of Phoenician origin; see tww in Semitic roots.