- 1 [countable, uncountable] the 25th letter of the English alphabet “Year” begins with (a) Y/“Y.”
- 2[uncountable] (mathematics) used to represent a number whose value is not mentioned Can the value of y be predicted from the value of x?
- 3[uncountable] a person, a number, an influence, etc. that is not known or not named Let's suppose X knows what Y is doing. see also Y chromosome
NAmE//waɪ//y (pl. Ys, Y's, y's