y or Y 
/ˈwaɪ/ noun
plural y's or ys or Y's or Ys /ˈwaɪz/ /ˈwaɪ/ noun 1 : the 25th letter of the English alphabet [count] ▪ a word that starts with a y [noncount] ▪ a word that starts with y 2 [noncount] mathematics — used to represent especially a second unknown quantity ▪ If x + y = 5 and x – y = 3, what are the values of x and y? 3 [noncount] — used in the phrase x, y, and z to refer to the second thing in a group of three unnamed things ▪ People keep giving me advice about it, saying I should do x, y, and z. 4 [count] : something that is shaped like a Y
▪ Turn left when you come to the Y. [=when the road/path splits like the top half of a Y] 5 the Y US, informal : the YMCA or the YWCA
▪ I'm going to the Y after work tonight.
▪ Turn left when you come to the Y. [=when the road/path splits like the top half of a Y]
▪ I'm going to the Y after work tonight.
