noun
or X /ˈɛks/ , pl x's or xs or X's or Xs /ˈɛksəz/
the 24th letter of the English alphabet [count]
[count] :the Roman numeral that means
[noncount] mathematics
a - used to represent an unknown quantity
b - used as a symbol for multiplication
[noncount] - used as a symbol between the numbers of a measurement
[noncount] :an unknown thing, person, or quantity
[noncount] - used in the phrase x, y, and z to refer to the first thing in a group of three unnamed things
[count] - used as a mark at the end of a letter, an e-mail, etc., to represent a kiss
[count] - used like a signature by a person who cannot write;
[count] - used on a map or picture to show where someone or something is
[count] - used as a mark to show who or what you are voting for or choosing;
verb
x-es also x's or xes /ˈɛksəz/; x-ed also x'd or xed /ˈɛkst/; x-ing or x'ing /ˈɛksɪŋ/
x out
[phrasal verb]
x (something) out or x out (something) :to draw an x or a series of x's through (something) to show that it is wrong or not wanted
US