Meaning of Y in English

Y

/ waɪ; NAmE / noun , abbreviation

■ noun (also y ) ( pl. Ys , Y's , y's / waɪz; NAmE /)

1.

[ C , U ] the 25th letter of the English alphabet :

'Year' begins with (a) Y / 'Y'.

2.

[ U ] ( mathematics ) used to represent a number whose value is not mentioned :

Can the value of y be predicted from the value of x?

3.

[ U ] 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 , Y-fronts

■ abbreviation

the Y ( NAmE , informal ) YMCA , YWCA

Oxford Advanced Learner's English Dictionary.      Оксфордский английский словарь для изучающик язык на продвинутом уровне.