xp

As a noun pursuit

is the act of pursuing.

As an initialism XP is

initialism of eXtreme Programming|lang=en.

As an abbreviation XP is

"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.

Experimental is a initialism of xp.

As an adjective experimental

is experimental.

As an initialism xp is

(computing) or xp can be (us|military|aviation|obsolete) experimental pursuit fighter (prefix).

As an abbreviation xp is

(grammar|x-bar theory) "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.