- to cross out or mark with or as if with an x (often followed by out): to x out an error.
- to indicate choice, as on a ballot or examination (often followed by in): to x in the candidate of your choice.
Origin of x
- the 24th letter and 19th consonant of the modern English alphabet
- a speech sound sequence represented by this letter, in English pronounced as ks or gz or, in initial position, z, as in xylophone
- commerce banking finance ex
- maths the x- axis or a coordinate measured along the x- axis in a Cartesian coordinate system
- an algebraic variable
- (formerly, in Britain)
- indicating a film that may not be publicly shown to anyone under 18. Since 1982 replaced by symbol 18
- (as modifier)an X film
- denoting any unknown, unspecified, or variable factor, number, person, or thing
- (on letters, cards, etc) denoting a kiss
- (on ballot papers, etc) indicating choice
- (on examination papers, etc) indicating error
- for Christ; Christian
- (Roman numeral) tenSee Roman numerals
Word Origin and History for x out
most English words beginning in -x- are of Greek origin or modern commercial coinages. East Anglian in 14c. showed a tendency to use -x- for initial sh-, sch- (cf. xal for shall), which didn't catch on but seems an improvement over the current system. As a symbol of a kiss on a letter, etc., it is recorded from 1765. In malt liquor, XX denoted "double quality" and XXX "strongest quality" (1827).
Algebraic meaning "unknown quantity" (1660 in English), sometimes said to be from medieval use, originally a crossed -r-, probably from Latin radix (see root (n.)). Other theories trace it to Arabic, but a more prosaic explanation says Descartes (1637) took x, y, z, the last three letters of the alphabet, for unknowns to correspond to a, b, c, used for known quantities.
Used allusively for "unknown person" from 1797, "something unknown" since 1859. As a type of chromosome, attested from 1902 (first so called in German; Henking, 1891). First used 1950 in Britain to designate "films deemed suitable for adults only;" adopted in U.S. Nov. 1, 1968.