Unfriend

Unfriended :(

The Oxford English Dictionary declares "unfriend" the Word of the Year 2009.

unfriend – verb – To remove someone as a ‘friend’ on a social networking site such as Facebook.

“'It has both currency and potential longevity,' notes Christine Lindberg, Senior Lexicographer for Oxford’s US dictionary program. 'In the online social networking context, its meaning is understood, so its adoption as a modern verb form makes this an interesting choice for Word of the Year. Most 'un-' prefixed words are adjectives (unacceptable, unpleasant), and there are certainly some familiar 'un-' verbs (uncap, unpack), but 'unfriend' is different from the norm. It assumes a verb sense of 'friend' that is really not used (at least not since maybe the 17th century!). Unfriend has real lex-appeal.'"

Via the Oxford University Press Blog