X 1
(also x )
■ noun ( plural Xs or X's )
1》 the twenty-fourth letter of the alphabet.
2》 denoting the next after W in a set of items, categories, etc.
3》 denoting an unknown or unspecified person or thing.
4》 (usu. x ) the first unknown quantity in an algebraic expression.
↘denoting the principal or horizontal axis in a system of coordinates.
5》 a cross-shaped written symbol, used:
↘to indicate a position on a map.
↘to indicate an incorrect answer.
↘to symbolize a kiss.
↘to indicate one's vote on a ballot paper.
6》 the Roman numeral for ten.
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X 2
■ symbol films classified as suitable for adults only (replaced in the UK in 1983 by 18 , and in the US in 1990 by NC–17 ).
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X 3
■ abbreviation N. Amer. informal the drug Ecstasy.