Today's word is unfriended, and thank you to Jenny for this one. Unless I have remembered it wrongly. The term refers to your removal as someone's Facebook or Myspace friend. I guess in Linked In the synonym would be unconnected or unconnectioned.
The word is pretty well attested, and the Wiktionary even adds comparative and superlative - more unfriended and most unfriended. The Urban Dictionary, always useful, gives exactly the definition one would expect, and this example "Wow, all I did was post a slightly suggestive picture in his profile and next thing I know I'm unfriended."
And as you would expect, friended, from the verb to friend, meaning to add someone as a Facebook friend. This is also now fully entrenched as a word, according to the Urban Dictionary - the best guide to the language of modern life in the west.