Definition of "XP"
XP1
noun
uncountable
(software engineering) Initialism of Extreme Programming.
(medicine) Initialism of Xeroderma Pigmentosum.
noun
plural XP
(roleplaying games) Initialism of Experience Point.
XP2
prefix
(aviation, military, obsolete, US) eXperimental, Pursuit, fighter (prefix)
XP3
noun
plural XPs
(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.)