I. X 1 BrE AmE , x /eks/ ( plural X’s , x’s ) noun
1 . LETTER [uncountable and countable] the 24th letter of the English alphabet
2 . NUMBER [countable] the number 10 in the system of ↑ roman numeral s
3 . MATHEMATICS [uncountable] technical a letter used in mathematics to represent an unknown quantity or value:
if 3x = 6, x = 2
4 . ON SCHOOL WORK [countable] a mark used on school work to show that a written answer is not correct
5 . WHEN VOTING [countable] a mark used to show that you have chosen something on an official piece of paper, for example when voting
6 . ON A LETTER [countable] a mark used to show a kiss, especially at the end of a letter:
Love, Cindy XXX
7 . FILM [singular, uncountable] used in the past to describe a film that was officially approved as only suitable for people over 18 SYN 18 ⇨ ↑ X-rated
8 . UNKNOWN/SECRET NAME [uncountable] a letter used instead of someone’s or something’s real name because you want to keep it secret or you do not know it:
At the trial, Ms X said that she had known the defendant for three years.
9 . WHEN SIGNING YOUR NAME [countable] a mark used instead of a signature by someone who cannot write
10 . X number of people/things used to say that there are a number of people or things when the exact number is not important
11 . X marks the spot used on maps in adventure stories to show that something is buried in a particular place
II. X 2 BrE AmE verb
X something ↔ out phrasal verb
American English to mark or remove a mistake in a piece of writing using an X SYN cross out