X, letter. The twenty-fourth letter of the basic modern Latin alphabet.

X, symbol. A symbol of the IPA, representing a voiceless uvular fricative.

X, symbol. (bowling) strike

X, symbol. A hazard indicator, sometimes incorporated into standard labelling and signage systems

X, letter. The twenty-fourth letter of the English alphabet, called ex and written in the Latin script.

X, noun. Any mark that looks like that letter, such as such a mark made by a person who cannot read or write, in lieu of a signature.

X, noun. (lacrosse) The spot behind the goal.

X, noun. (slang) Ecstasy, a particular street drug.

X, adjective. (Former British film certificate) Suitable only for those aged 16 or (later) 18 years and over.

X, adjective. (movie rating) Obscene.

X, proper noun. (informal) Christ

X, noun. (North America) cross, crossing

X, noun. Intersex or transgender (passports and identification documents)

X, noun. One of the tristimulus values which, with Y and Z, defines coordinates in a three-dimensional color space. Pronounced big X or cap X.

Ⅹ, symbol. Roman numeral ten (10)

Ⅹ, symbol. (ordinal) (especially in the names of aristocracy) the tenth.

X, letter. The twenty-fourth letter of the basic modern Latin alphabet.

X, symbol. (IPA) voiceless velar fricative.

X, symbol. (mathematics) An unknown variable.

X, symbol. (mathematics) The first coordinate in Cartesian coordinates, representing horizontal position.

X, symbol. Used as a placeholder for a digit or value that may vary.

X, symbol. A kiss at the end of a letter, or similar missive.

X, symbol. (computing) A unit of transfer rate of CD drives, equal to 150 KiB per second.

X, symbol. (computing) A unit of transfer rate of DVD drives, equal 1.32 MiB per second.

X, letter. The twenty-fourth letter of the English alphabet, called ex and written in the Latin script.

X, abbreviation. Intersex or transgender (passports and identification documents)

X, conjunction. (fandom) Used between the names of two characters to denote a ship, particularly in anime, manga, and video games.

Ⅹ, symbol. Ⅹ, the Roman numeral ten (10)

Ｘ, letter. The letter X in fullwidth.

Ｘ, letter. The letter x in fullwidth.

Ẋ, letter. The letter X with a dot above.

Ẋ, letter. The letter x with a dot above.

Ẍ, letter. The letter x with a diaeresis above.

X BOSON, noun. (physics) A hypothetical elementary particle that couples quarks to leptons, analogous to the W boson and Z boson, but corresponding to a new type of force predicted by the Georgi–Glashow model.

X BOSONS, noun. Plural of X boson

X CHROMOSOME, noun. (genetics) A mammalian sex chromosome. Cells of females have a pair of X chromosomes while cells of males have an X and a Y.

X CHROMOSOMES, noun. Plural of X chromosome

X FACTOR, noun. (idiomatic) An unknown or hard-to-define influence; a factor with unknown or unforeseeable consequences.

X FACTOR, noun. Prothrombinase, also called factor X.

X FACTOR, noun. (astrophysics) The proportionality constant which converts CO emission line brightness to molecular hydrogen mass.

X FACTOR, noun. Alternative spelling of X factor

X FACTORS, noun. Plural of X factor

X FACTORS, noun. Plural of x factor

X MARK, noun. A symbol comprised of two perpendicular lines (✗), especially when representing negation or lack of verification.

X MARKS, noun. Plural of X mark

X OUT, verb. To cross out with letter X's, or with scribble, or with lines.

X PRIZE, noun. A prize, usually a multi-million dollar monetary one, offered for a specific scientific or technological advance.

X X, symbol. (emoticon) The face of a dead person.

X, noun. The cardinal number that is the sum of nine and one; the base of the decimal system.

X, noun. The 24th letter of the Roman alphabet.

X, noun. Street names for methylenedioxymethamphetamine.

X, adjective. Being one more than nine.