noun: (software engineering) Initialism of Extreme Programming.
noun: (medicine) Initialism of Xeroderma Pigmentosum.
noun: (role-playing games) Initialism of Experience Point.
noun: (motor racing) Abbreviation of extreme prix; xPrix.; from being an extreme grand prix.
noun: (computing) Ellipsis of Windows XP.
noun: (grammar, X-bar theory) Initialism of X Phrase. (a phrase which consists of either: (1) an optional specifier and an X-bar phrase, or (2) a conjunction sandwiched between two other XPs. The X is a "pro-letter" which can be substituted by letters such as N for noun, V for verb, P for preposition, I for inflectional, etc.)
