YBrE/waɪ/NAmE/waɪ/noun (also y) (Ys, Y's, y'sBrE/waɪz/NAmE/waɪz/) [C, U]the25thletteroftheEnglishalphabet英语字母表的第 25 个字母◆'Year'beginswith (a) Y/'Y'.year 一词以字母 y 开头。[U](mathematics数学) usedtorepresentanumberwhosevalueisnotmentioned(代表未知数)◆Canthevalueofybepredictedfromthevalueofx? 能从 x 值推知 y 值吗?[U]aperson, anumber, aninfluence, etc. thatisnotknownornotnamed未知的人(或数、影响等);未指明的人(或数、影响等)◆Let'ssupposeXknowswhatYisdoing. 假设 X 知道 Y 正在干什么。➡ see alsoY chromosome, Y-Fronts™