> as lemmas

1618 G. Chapman tr. Hesiod Georgicks i.14 And this paineful passage to Vertue Virgil imitated in his translation of the Pythagorean letter, Y.

1789 M. Madan tr. Persius Satires v, in New & Literal Transl. Juvenal & Persius II. 404 Compitum is a place where two or more ways meet.—The poet here alludes to the Pythagorean letter Y.

1851 Encycl. Americana (new ed.) XIII. 296/1 Y, in its Greek form (Υ), is also called the Pythagorean letter, because the Pythagoreans were said to signify by it the proceeding of the duad out of the monad, or the sacred triad..or the dividing road of life.

1929 S. Angus Relig. Quests Graeco-Roman World xvii. 308 The symbolic Pythagorean letter Upsilon divides the scene into two sections: on the right Virtue is seated as a woman with a little child.

1989 D. A. Carozza & H. J. Shey Petrarch's Secretum 146 The Pythagorean letter was ‘Y’, which by its form became in the Middle Ages a symbol for man's life. At a certain point every man makes a decisive step in the direction of virtue or pleasure.