- the 24th letter of the English alphabet, a consonant.
- any spoken sound or combination of sounds represented by the letter X or x, as in xylene, box, or exact.
- something having the shape of an X.
- a written or printed representation of the letter X or x.
- a device, as a printer's type, for reproducing the letter X or x.
- 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
- an unknown quantity or a variable.
- (used at the end of letters, telegrams, etc., to indicate a kiss.)
- (used to indicate multiplication) times: 8 × 8=64.
- (used between figures indicating dimensions) by: 3″ × 4″ (read: “three by four inches”); 3″ × 4″ × 5″ (read: “three by four by five inches”).
- power of magnification: a 50x telescope.
- (used as a signature by an illiterate person.)
- crossed with.
- (used to indicate a particular place or point on a map or diagram.)
- out of; foaled by: a colt by Flag-a-way x Merrylegs.
- (used to indicate choice, as on a ballot, examination, etc.)
- (used to indicate an error or incorrect answer, as on a test.)
- Mathematics. (in Cartesian coordinates) the x-axis.
- Chess. captures.
- a person, thing, agency, factor, etc., of unknown identity.
- the 24th in order or in a series, or, when I is omitted, the 23rd.
- (sometimes lowercase) the Roman numeral for 10.Compare Roman numerals.
- Electricity. reactance.
- Slang. a ten-dollar bill.
- (in the U.S.) a rating of the Motion Picture Association of America for movies with subject matter that is suitable for adults only: persons who are under age (usually 17) will not be admitted.Compare G(def 7), PG, PG-13, R1.
- (in Great Britain) a designation for a film recommended for adults only.Compare A(def 11), AA(def 5), U(def 6).
- a person, thing, agency, factor, etc., of unknown identity.
- Chemistry. (formerly) xenon.
- the twenty-second letter of the Greek alphabet (X, χ).
- the consonant sound represented by this letter.
Origin of chi1
Related Words for xunnamed, unheard-of, unexplored, exotic, unidentified, remote, undiscovered, unfamiliar, foreign, strange, anonymous, new, nameless, uncharted, unexplained, unrecognized, undisclosed, unsigned, streak, impression
Examples from the Web for x
Contemporary Examples of x
“Getting out of X band is on option,” said one senior Air Force official.Pentagon Worries That Russia Can Now Outshoot U.S. Stealth Jets
December 4, 2014
A bunch of old, white, rock titans come together with young, white, X Factor hotties to persuade Britain to heal Africa.Do They Know It’s Time to Stop Band Aid?
November 22, 2014
His company names all ended in an X—EBX, OGX, MMX—because in numerology, X stands for the multiplication of wealth.The Zillionaires Who Lost Everything
October 26, 2014
X was then warned of the near miss via a correspondent who had worked with him in the past.
He said that he had secured the fixer, ‘X,’ through a fellow Western journalist, and not by writing to 30 Syrians via Facebook.
Historical Examples of x
I have let X equal the unknown quantity, but I don't know Y.
"Why—er—well, there's the most competition on the X & Y Road," he said, slowly.Four Girls and a Compact
Annie Hamilton Donnell
And the 'X' would indicate that it is inhabited, but not by intelligent beings.The Death-Traps of FX-31
Sewell Peaslee Wright
X received this declaration with his usual woodenness and went on.A Set of Six
The X's, Flossie explained, indicated kisses—a dozen to an X.In a Little Town
- 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 for X
- the 22nd letter of the Greek alphabet (Χ, χ), a consonant, transliterated as ch or rarely kh
ch'i or qi
- (sometimes capital) (in Oriental medicine, martial arts, etc) vital energy believed to circulate round the body in currents
Word Origin for chi
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.
22nd letter of the Greek alphabet, representing a -kh- sound (see ch). The letter is shaped like an X, and so the Greek letter name was used figuratively to signify such a shape or arrangement (e.g. khiasma "two things placed crosswise;" khiastos "arranged diagonally; marked with an X;" khiazein "to mark with an 'X', to write the letter 'X'"). Some dialects used chi to represent the -ks- sound properly belonging to xi; Latin picked this up and the sound value of chi in Latin-derived alphabets is now that of English X.