xxxx

Definition(s) of “X”

-x

suffix

forming the plural of many nouns ending in -u taken from French: : tableaux.

ORIGIN from French.

X 1 |eks| (also x)

noun ( pl. Xs or X's )

1 the twenty-fourth letter of the alphabet.

denoting the next after W in a set of items, categories, etc.

denoting an unknown or unspecified person or thing : there is nothing in the data to tell us whether X causes Y or Y causes X.

( x) (used in describing play in bridge) denoting an unspecified card other than an honor.

(usu. x ) the first unknown quantity in an algebraic expression, usually the independent variable. [ORIGIN: the introduction of x, y, and z as symbols of unknown quantities is due to Descartes ( Géométrie, 1637), who took z as the first unknown and then proceeded backward in the alphabet.]

(usu. x ) denoting the principal or horizontal axis in a system of coordinates : [in combination ] the x -axis.

2 a cross-shaped written symbol, in particular

used to indicate a position on a map or diagram.

used to indicate a mistake or incorrect answer.

used in a letter or message to symbolize a kiss.

used to indicate one's vote on a paper ballot.

used in place of the signature of a person who cannot write.

3 a shape like that of a letter X : two wires in the form of an X | [in combination ] an X-shaped cross.

4 the Roman numeral for ten.

verb ( X’s, X’d, X’ing) [ trans. ]

mark or make a sign with an X.

overwrite or obliterate with an X or series of X’s.

make void or annul; invalidate : we’re all X-ing things out of our curricula.

X 2

symbol

1 a rating assigned to movies classified as suitable for adults only. Replaced in 1990 by NC-17 .

2 (in systematic names of organisms) hybrid. [ORIGIN: from cross noun 3. ]