(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.

plural of X boson

Alternative form of Gen X.

X-class submarine

lyonization

plural of X-mas

(informal) Of, pertaining to, or characteristic of the paranormal investigation science fiction television series The X-Files.

(archaic) X-ray radiation

(astronomy) An alternate name for a transneptunian object.

Synonym of triple X syndrome