- Tau (Wikipedia)
Tau /ΛtΙΛ, ΛtaΚ/ (uppercase Ξ€, lowercase Ο, or Ο; Greek: ΟΞ±Ο
[taf]) is the 19th letter of the Greek alphabet, representing the voiceless dental or alveolar plosive IPA: [t]. In the system of Greek numerals, it has a value of 300.