- 1 [countable, uncountable] the 24th letter of the English alphabet ‘Xylophone’ begins with (an) X/‘X’.
- 2 [uncountable] (mathematics) used to represent a number whose value is not mentioned The equation is impossible for any value of x greater than 2.
- 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 X chromosome, X-rated, X-ray
X
nounBrE BrE//eks//; NAmE NAmE//eks//
(also x) (pl. Xs, X’s, x’s BrE BrE//ˈeksɪz//; NAmE NAmE//ˈeksɪz//
)Check pronunciation: X
