plural x's or xs
ˈek-səz 
often capitalized, often attributive
1
a
: the 24th letter of the English alphabet
b
: a graphic representation of this letter
c
: a speech counterpart of orthographic x
2
: ten see Table of Numbers
3
: a graphic device for reproducing the letter x
4
: 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
5
: an unknown quantity
6
: something shaped like or marked with the letter X
1
: to mark with an x
2
: to cancel or obliterate with a series of x's
—usually used with out
x-ed out the mistake
1
cross
2
ex
3
experimental
4
extra
1
2
by
—used in nonmathematical constructions
He drove a 4x4 vehicle.
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
Synonyms
Dictionary Entries Near x
Cite this Entry
“X.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/x. Accessed 30 Nov. 2024.
Copy CitationKids Definition
x
1 of 3 nounoften capitalized
1
: the 24th letter of the English alphabet
2
: ten in Roman numerals
3
: an unknown quantity
X
3 of 3 adjective
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
x
2 of 2 symbol1
capitalized
halogen atom
—used in general formulas (as of trihalomethane CHX3)
2
power of magnification
Legal Definition
x
1 of 2 nounoften capitalized
1
: 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)
2
: a mark used in indicating a choice or applicable item (as on an insurance form)
x
2 of 2 abbreviation1
ex-distribution
2
ex-dividend
3
ex-rights
4
ex-warrants
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