Tau

·add. ·noun The nineteenth letter (/, /) of the Greek alphabet, equivalent to English t.

II. Tau ·noun The common American toadfish;

— so called from a marking resembling the Greek letter tau (/).

tau
tau, n. indecl., a Celtic word of unknown meaning, Verg. Cat. ap. Quint. 8, 3, 28; cf. Aus. Idyll. 1...

A New Latin Dictionary by Charlton T. Lewis Ph.D. and Charles Short, LL. D.