Y

Y (ī), pron. I. [Obs.] King Horn. Wyclif.

Y (wī). Y, the twenty-fifth letter of the English alphabet, at the beginning of a word or syllable, except when a prefix (see Y-), is usually a fricative vocal consonant; as a prefix, and usually in the middle or at the end of a syllable, it is a vowel. See Guide to Pronunciation, §§ 145, 178-9, 272.

It derives its form from the Latin Y, which is from the Greek Υ, originally the same letter as V. Etymologically, it is most nearly related to u, i, o, and j. g; as in full, fill, AS. fyllan; E. crypt, grotto; young, juvenile; day, AS. dæg. See U, I, and J, G.

☞ Y has been called the Pythagorean letter, because the Greek letter Υ was taken represent the sacred triad, formed by the duad proceeding from the monad; and also because it represents the dividing of the paths of vice and virtue in the development of human life.

Y (wī), n.; pl. Y's (wīz) or Ys. Something shaped like the letter Y; a forked piece resembling in form the letter Y. Specifically: (a) One of the forked holders for supporting the telescope of a leveling instrument, or the axis of a theodolite; a wye. (b) A forked or bifurcated pipe fitting. (c) (Railroads) A portion of track consisting of two diverging tracks connected by a cross track.

Y level (Surv.), an instrument for measuring differences of level by means of a telescope resting in Y's. -- Y moth (Zoöl.), a handsome European noctuid moth Plusia gamma) which has a bright, silvery mark, shaped like the letter Y, on each of the fore wings. Its larva, which is green with five dorsal white species, feeds on the cabbage, turnip, bean, etc. Called also gamma moth, and silver Y.