Word Study
tau
CIDE DICTIONARY
tau, n. [Gr. tay^.].
The nineteenth letter (t. [Webster 1913 Suppl.]
tau, n. [Gr. tay^ the letter T).].
The common American toadfish; -- so called from a marking resembling the Greek letter tau (1913 Webster]
OXFORD DICTIONARY
tau, n. the nineteenth letter of the Greek alphabet (T).
Idiom
tau cross a T-shaped cross. tau particle Physics an unstable, heavy, and charged elementary particle of the lepton class.
Etymology
ME f. Gk
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