Y

Y 25th letter of the alphabet . It was a Latin importation of the eastern Greek upsilon (see U ), which was pronounced like ü; the Romans used it for Greek words. In English y mainly represents the semivowel occurring in words such as yet; the same semivowel is the second member of the diphthongs ā, ē, ī, and oi. The modern ignorant use of y in ye for the (as in "Ye Olde Shoppe" ) is based on a misreading of an old sign for th. In chemistry Y is the symbol for the element yttrium .

y • abbr. year(s): orbital period (Pluto): 248.5y.

Y¹ / wī/ (also y) • n. (pl. Ys or Y's ) 1. the twenty-fifth letter of the alphabet. ∎  denoting the next after X in a set of items, categories, etc. ∎  denoting a second unknown or unspecified person or thing: the claim that chemical X causes birth defect Y. ∎  (usu. y) the second unknown quantity in an algebraic expression, usually the dependent variable. ∎  (usu. y) denoting the secondary or vertical axis in a system of coordinates: [in comb.] the y-axis. 2. (Y) a shape like that of a capital Y: [in comb.] rows of tiny Y-shaped motifs. Y² • abbr. ∎  yen: Y140. ∎ inf. a YMCA, YWCA, YMHA, or YWHA facility: Scott was living at the Y. • symb. the chemical element yttrium.