A pair of flat or curved stretchers, on a chair etc., that often have a knob at the intersection

(genetics) Alternative spelling of X chromosome

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

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

Pornographic or indecent. / Denoting a film given an X classification.

plural of X-ray

Third-person singular simple present indicative form of X-ray

(fandom slang) A fan of the television series The X-Files.

(originally) A generation of people whose future is uncertain; a lost generation.

Alternative form of Xmas