Y

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.

Something shaped like the letter Y; a forked piece resembling in form the letter Y. Specifically:

One of the forked holders for supporting the telescope of a leveling instrument, or the axis of a theodolite; a wye.

A forked or bifurcated pipe fitting.

I. [Obs.] King Horn. Wyclif.