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  • x
    x
    verb (used with object)
    to cross out or mark with or as if with an x (often followed byout ).
  • X
    X
    noun
    the 24th letter of the English alphabet, a consonant.
Synonyms

x

1 American  
[eks] / ɛks /

verb (used with object)

x-ed, x'd, x-ing, x'ing
  1. to cross out or mark with or as if with an x (often followed byout ).

    to x out an error.

  2. to indicate choice, as on a ballot or examination (often followed byin ).

    to x in the candidate of your choice.


x 2 American  

abbreviation

  1. ex.

  2. excess.

  3. Stock Exchange.

    1. (of stock trading) ex dividend.

    2. (of bond trading) ex interest.

  4. experimental.

  5. extra.


x 3 American  
Symbol.
  1. an unknown quantity or a variable.

    1. the letter x used to replace or obscure a gender morpheme, as to avoid the -o or -a inflection of a word borrowed from Spanish or the sequence m-e-n in the word women . See Latinx, womxn.

    2. the letter x indicating a variable and used to hold a place in a word or abbreviation that can be occupied by another letter, as in CxO to account for a range of specialized executive positions in a corporation, for example CEO , CFO , and COO .

  2. (used at the end of letters, telegrams, etc., to indicate a kiss.)

  3. (used to indicate multiplication) times.

    8 × 8=64.

  4. (used between figures indicating dimensions) by.

    3″ × 4″ (read: “three by four inches”);

    3″ × 4″ × 5″ (read: “three by four by five inches”).

  5. power of magnification.

    a 50x telescope.

  6. (used as a signature by an illiterate person.)

  7. cross.

  8. crossed with.

  9. (used to indicate a particular place or point on a map or diagram).

    X marks the spot where the pirates' treasure is buried.

  10. out of; foaled by.

    a colt by Flag-a-way x Merrylegs.

  11. (used to indicate choice, as on a ballot, examination, etc.)

  12. (used to indicate an error or incorrect answer, as on a test.)

  13. Mathematics. (in Cartesian coordinates) the x-axis.

  14. Chess. captures.

  15. a person, thing, agency, factor, etc., of unknown identity.

    I feel sorry for poor Mr. X, the man she will ultimately marry.


X 4 American  
[eks] / ɛks /
Or x

noun

  • X's,
    plural
  • Xs,
    plural
  • x's,
    plural
  • xs
    plural
  1. the 24th letter of the English alphabet, a consonant.

  2. any spoken sound or combination of sounds represented by the letter X or x, as in xylene, box, or exact.

  3. something having the shape of an X .

  4. a written or printed representation of the letter X or x.

  5. a device, as a printer's type, for reproducing the letter X or x.


X 5 American  

abbreviation

  1. experimental.

  2. extra.

  3. extraordinary.


X 6 American  
Symbol.
  1. the 24th in order or in a series.

  2. (sometimes lowercase) the Roman numeral for 10.

  3. Christ.

  4. Christian.

  5. cross.

  6. Electricity. reactance.

  7. Slang. a ten-dollar bill.

  8. (no longer in official use by the Motion Picture Association of America) a rating for movies with subject matter that is suitable for adults only.

  9. (in Great Britain) a designation for a film recommended for adults only.

  10. a person, thing, agency, factor, etc., of unknown identity.

  11. Chemistry. (formerly) xenon.


X 1 British  

symbol

    1. indicating a film that may not be publicly shown to anyone under 18. Since 1982 replaced by symbol 18

    2. ( as modifier )

      an X film

  1. denoting any unknown, unspecified, or variable factor, number, person, or thing

  2. (on letters, cards, etc) denoting a kiss

  3. (on ballot papers, etc) indicating choice

  4. (on examination papers, etc) indicating error

  5. for Christ; Christian

  6. ten See Roman numerals

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

x 2 British  

symbol

  1. commerce banking finance ex

  2. maths the x- axis or a coordinate measured along the x- axis in a Cartesian coordinate system

  3. an algebraic variable

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

x 3 British  
/ ɛks /

noun

  1. the 24th letter and 19th consonant of the modern English alphabet

  2. a speech sound sequence represented by this letter, in English pronounced as ks or gz or, in initial position, z, as in xylophone

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

Noun Inflected Forms

Etymology

Origin of x

First recorded in 1840–50

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

Hottle played a young orphan named Jia in the monster film series, and reprised the role in the 2024 sequel Godzilla x Kong: The New Empire.

From BBC Jul. 22, 2026

With two years of operation, it could also map sodium, while improving the grid size to 30 x 30 kilometers.

From Science Daily Jun. 6, 2026

For his readers, Mr. Elwes makes this number more manageable with another tool, exponentiation: There are 107 x 1060 = 1067 monkeys.

From The Wall Street Journal May 29, 2026

You are allowed to bring in a backpack 18” x 13” x 8.5” or smaller.

From Los Angeles Times Apr. 1, 2026

Imagined the solutions, x - 3 and x = -7, and felt a little better.

From "The Lions of Little Rock" by Kristin Levine

Follow Belle Lin on LinkedIn and X for her latest reporting on enterprise technology and AI.

From The Wall Street Journal Aug. 3, 2026

Attached to Blanche's post on X was an unsigned memo in which he said the IRS immunity would be limited to the "named parties in the lawsuit".

From BBC Aug. 3, 2026

In a second post, Newsom amplified a post on X that shows how the prices of items like rice, cotton and wheat have increased since the start of the year.

From Los Angeles Times Aug. 3, 2026

US Treasury Secretary Scott Bessent posted on X that "we will not hesitate to participate in further joint intervention", citing economic security and the US-Japan alliance as some of the reasons behind it.

From Barron's Aug. 3, 2026

You all line up and make an X with your wrists in the air as you pace along to the music.

From "Black Swan Green" by David Mitchell

MT: How do you feel about Gen X’s legacy as basically the coolest generation?

From Los Angeles Times Jun. 25, 2026

He said X's commitments were "a step forward, but there's a lot more to do".

From Barron's May 15, 2026

X's second commitment is to withhold UK access to accounts reported for posting UK illegal terrorist content, if it determines they are operated by, or on behalf of, a terrorist organisation proscribed in the UK.

From BBC May 15, 2026

That came after a February raid on X’s Paris offices by French law enforcement and prosecutors seeking evidence in their probe.

From The Wall Street Journal May 7, 2026

Soon I read in the various newspapers that rumors were being heard of threats on Malcolm X’s life.

From "The Autobiography of Malcolm X" by Alex Malcolm X;Hailey

The book also says when to try for a 2-point conversion, whether to attempt an onside kick or to kick deep and how to manage the two-minute warning—nearly everything outside of Xs and Os.

From The Wall Street Journal Oct. 17, 2025

The TikToks, Instagrams, and Xs of the world would rather nobody be worried about screen time at all, even as a few of those apps allow users to set their own limits.

From Slate Sep. 5, 2025

It is often called a violent chess match, and if you have ever seen inside a playbook and seen each play drawn up in Xs and Os fashion, you would have to agree.

From BBC Feb. 7, 2025

To Sirianni, Kehres was much more than a guy with a whistle, or someone who could draw up Xs and O’s.

From Los Angeles Times Feb. 5, 2025

The hinges on the cabinets were Ls, the water faucets were Xs, the burners on the stove stood up on neat N legs.

From "Chasing Vermeer" by Blue Balliett

But there are other cases in which scholars can only guess about the origins of x’s role, such as the phrase “X marks the spot.”

From Scientific American Aug. 10, 2023

Mr Musk says "tweets" will be replaced too, with posts to be called "x's" instead.

From BBC Jul. 25, 2023

Nearby in a tent, 30-ish chairs sat on spaced out yellow x’s.

From Slate Jan. 14, 2021

Note that removing the x’s from x +x 5 would be like cancelling the 2’s in the fraction 2 + 5 !

From Textbooks Apr. 22, 2020

Once the guppies turn into x's and y’s, my contacts fog.

From "Speak" by Laurie Halse Anderson

Item for the Tretys of Werre in iiij. books, which conteyneth lx. levis, after ijd. a leaff xs.

From The Boke of Noblesse by Unknown

Paide the smythe for making a new clapper for the great bell, xs.

From Notes and Queries, Vol. III, Number 86, June 21, 1851 A Medium of Inter-communication for Literary Men, Artists, Antiquaries, Geneologists, etc. by Various

So he said "Didn't you never correspond with a girl and put some of them xs down to the bottom of your letter?"

From The Real Dope by Lardner, Ring

Then follow "the names of those who were served with this writt, and who most willingly obeyed upon the receipt thereof," contributing altogether xvili xs 0.

From Christmas: Its Origin and Associations Together with Its Historical Events and Festive Celebrations During Nineteen Centuries by Dawson, William Francis

They imprint certain cabalistic tokens of ownership on the logs,--crosses, xs, stars, crescents, alphabetical letters,--marks respected all along the rivers and lakes down to the boom where the sticks are garnered for market.

From The Atlantic Monthly, Volume 10, No. 58, August, 1862 by Various

I self-consciously x’d out of my browser window, open to three Blythe Harris platforms.

From The Guardian Oct. 18, 2014

Some Tottall of the Allowances and paymentes—M,ciijviij'li. viij's. x'd.

From Notes and Queries, Number 01, November 3, 1849 by Various

I got out the chart from its case on the suit's belt, x'd the location, and went on, feeling more lonely all the time.

From Attrition by Krenkel, Roy G.

As he scrolled, read, clicked, and x-ed, Tess started coming up with her own ideas on how to birdnap.

From "As Brave As You" by Jason Reynolds

He x-ed out of Google, then sank back into the chair, his head in his hands.

From "As Brave As You" by Jason Reynolds

Acknowledging the Pentagon expulsions, Iran’s embassy in South Africa posted photos on social media Friday x-ing out portraits of several top U.S. military officials fired in recent months.

From Los Angeles Times Apr. 5, 2026

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