'Tau' definitions:
Definition of 'tau'
From: WordNet
noun
The 19th letter of the Greek alphabet
Definition of 'Tau'
From: GCIDE
- Tau \Tau\ (tou), n. [Gr. tay^.] The nineteenth letter ([Tau], [tau]) of the Greek alphabet, equivalent to English t. [Webster 1913 Suppl.]
Definition of 'Tau'
From: GCIDE