() 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.
(n.) Something shaped like the letter Y; a forked piece resembling in form the letter Y.
(n.) One of the forked holders for supporting the telescope of a leveling instrument, or the axis of a theodolite; a wye.
(n.) A forked or bifurcated pipe fitting.
(n.) A portion of track consisting of two diverging tracks connected by a cross track.