Tau

Tau (tou), n. [Gr. tay^.] The nineteenth letter (Τ, τ) of the Greek alphabet, equivalent to English t.

Tau (?), n. [Gr. tay^ the letter τ (English T).] (Zoöl.) The common American toadfish; -- so called from a marking resembling the Greek letter tau (τ).

Tau cross. See Illust. 6, of Cross.