TETRAD • E-FREE TRANSLATION.COM • Definition of Tetrad

... which we met afterwards. There quoth Panurge, Is it here? How many steps have you told? asked our magnificent lantern. One, two, three, four, answered Pantagruel. How much is that? asked she. Ten, returned he. Multiply that, said she, according to the same Pythagorical tetrad. That is, ten, twenty, thirty, forty, cried Pantagruel. How much is the whole? said she. One hundred, answered Pantagruel. Add, continued she, the first cube—that's eight. At the end of that fatal number you'll find the temple gate; and pray ...

— Gargantua and Pantagruel, Complete. • Francois Rabelais