x

1 of 5

noun

ˈeks

plural x's or xs ˈek-səz

often capitalized, often attributive

: the 24th letter of the English alphabet

: a graphic representation of this letter

: a speech counterpart of orthographic x

: ten see Table of Numbers

: a graphic device for reproducing the letter x

: one designated x especially as the 24th in order or class, or the first in an order or class that includes x, y, and sometimes z

: an unknown quantity

: something shaped like or marked with the letter X

2 of 5

verb

x-ed also x'd or xed ˈekst

; x-ing or x'ing ˈek-siŋ

transitive verb

: to mark with an x

: to cancel or obliterate with a series of x's

—usually used with out

x-ed out the mistake

3 of 5

abbreviation

cross

experimental

extra

4 of 5

symbol

times

2 x 3 = 6

The picture was enlarged 3x [=enlarged to three times the original size].

—used in measurements

an 8x11 sheet of paperAn early 20th century Persian Hamadan Gallery carpet with a camel hair ground, measuring 10.10 x 5.5.

The Magazine Antiques

—used in nonmathematical constructions

He drove a 4x4 vehicle.

5 of 5

adjective

ˈeks

of a motion picture

: of such a nature that admission is denied to persons under a specified age (such as 17)

—used before the adoption of NC-17

Example Sentences

Noun a word that starts with an x a word that starts with x

Word History

First Known Use

Noun

before the 12th century, in the meaning defined at sense 1a

Verb

circa 1849, in the meaning defined at sense 1

Adjective

1970, in the meaning defined above

Time Traveler

The first known use of x was before the 12th century

See more words from the same century

Cite this Entry

Style

“X.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/x. Accessed 7 Dec. 2022.

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Kids Definition

1 of 3 noun

ˈeks

often capitalized

: the 24th letter of the English alphabet

: ten in Roman numerals

: an unknown quantity

2 of 3 verb

x-ed also x'd or xed ˈekst

; x-ing or x'ing ˈek-siŋ

: to mark with an x

: to cancel with a series of x's

3 of 3 adjective

ˈeks

of a motion picture

: of such a nature that admission is denied to persons under a certain age (as 17)

—used before the adoption of NC-17

Medical Definition

1 of 2 noun

ˈeks

plural x's or xs or x'es or xes ˈek-səz

: the basic or monoploid number of chromosomes of a polyploid series : the number contained in a single genome compare n sense 1

2 of 2 symbol

capitalized halogen atom

—used in general formulas (as of trihalomethane CHX₃)

power of magnification

Legal Definition

1 of 2 noun

ˈeks

often capitalized

: a mark used in place of a signature when the maker is incapable of signing his or her name (as because of illiteracy or a physical ailment)

: a mark used in indicating a choice or applicable item (as on an insurance form)

2 of 2 abbreviation

ex-distribution

ex-dividend

ex-rights

ex-warrants

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x

noun

verb

abbreviation

symbol

adjective

Synonyms

Example Sentences

Word History

Dictionary Entries Near x

Cite this Entry

Kids Definition

Medical Definition

Legal Definition