Dictionary.net

the twenty-fifth letter of our alphabet.--Y=150; [=Y]=150,000.--ns. Y'-LEVEL, an engineers' spirit-level, so called because of the telescope formerly resting on 'Y's,' capable of being rotated at will--now substituted by the 'dumpy-level'--also Wye-level; Y'-MOTH, the gamma, a destructive noctuid moth, with a silvery Y-shaped mark on the upper wings; Y'-TRACK, a short track laid at right angles to a railway-line, connected with it by two switches resembling a Y, used instead of a turn-table for reversing engines.

See chappie

letter, (pl. Ys, Y\'s). (Alg.; y) second unknown quantity (cf. x, B); Y-shaped arrangement of lines, piping, roads, &c., forked clamp or support, (often attrib., as Y-branch, -cartilage, -joint, ligament; Y-cross, Y-shaped cross esp. on chasubles suggesting figure of crucified Christ; Y-level, surveying-level mounted on Ys; Y-moth, kind called also gamma with mark like Y or gamma on wings; Y-track, Y of railway-line with two branches running into main track enabling engine to reverse direction by running down one branch into stem& returning up the other. Abbr. (1): (Y.) young, Y.M.C.A., Y.W.C.A., (mens, womens, christian association). Abbr. (2): yd, yard; ye (pr. as the) the (y a survival in corrupt form of obs. b, symbol for th; still used as archaism); Yorks. (hire); yt (pr. as that) that (conj.; as ye above).

Middle English& still found in a few archaic forms (yclad clad, YCLEPT, ywis surely), repr. old English, Dutch., & German ge-as pref. of p.pp., collective nn., & other wds; the same element is seen under different forms in ALIKE, AMONG, AWARE, EITHER, ENOUGH, HANDIWORK.

suf. of abstract nn. & of adjj., repr. original Latin -ius -ia -ium, added directly to stem as in remedium remedy, furia fury, or to another suf. as in wds in -orius, -arius; also repr. Latin -ia f. Greek -ia. The suf. being unaccented in Latin, -i-was in normal French absorbed into the accented syllable, as in gloire, peremptoire, victoire, precaire, or disappeared, as in remede; but learned formations also occur in -ie& are common in mod. French, as in furie, centurie; & Latin or mod. Latin wds, whether thr. French or not, have in English the corresponding -y, as victory, glory, remedy, primary, peremptory; but many adjj. add a. new suf. as-OUS,-AL, (meritorious, monitorial).

Symbol of Yttriane.

Chemical symbol for the element yttrium.

See Wye.

With V and S, makes up the three letters represented by the Greek digamma.

the twenty-fifth letter of the English alphabet, derives its form from the Greek. At the beginning of words or syllables, it is called a consonant, produced by bringing the root of the tongue in close contact with the lower part of the palate, in the position in which the soft g is produced. Hence, y has been substituted for g in words of Anglo-Saxon origin, as year for gear, yellow for gealew. In the middle and at the end of words it is a vowel having precisely the same sounds as i, viz., a long sound, as in defy, and a short sound, as in synonymous, glory.