So on Facebook, you can click a little link below a photo, an ad, a link, or someone's status to "like" that thing. So if Aunt Esther has a wedding anniversary and can pull herself away from Farmville long enough to post a status about it, you can click this little link, and a little message will appear saying "Brigid Daull Brockway likes this!" with a little thumbs up next to it. In case you're too lazy to type the words "Congratulations Aunt Esther and Uncle Walter!" That is a lot of words, after all.
Now, ever since Facebook invented the "like" button, users have been loudly and ardently demanding a "dislike" button, so that if Aunt Esther pulls herself away from Farmville to tell you that Uncle Walter died, you can click a little link and a "Brigid Daull Brockway Dislikes This!" message could appear. Comforting people with casseroles is so last century.
NPR told me today that the reason Facebook won't keep its users happy and give us this much-needed tool (because it takes a really long time to just type out "Brigid Daull Brockway Dislikes This!") is that advertisers wouldn't like it very much. I can see where a company that pays for and maintains a Facebook page would not want people flocking to their page just to proclaim their hatred for it. Bad for business. Unless you ask Rebecca Black, who probably owes the omnipresence of her song Friday to the millions of people who posted and reposted the video just to make fun of it.
Side note: Yes, it's an incredibly annoying song. But she's a little girl and the Internet should probably stop collectively advocating her death. It's certainly no worse than, you know:
Although I do recall spending quite a bit of my tween years loudly advocating their deaths. And I'm not going to say I regret it.
But I digress as usual. Anyway, here are some terms for you, courtesy of my friends at the Online Etymology Dictionary:
Facebook (n): From 1983, when it referred to a directory with names and pictures; some colleges gave them out to Freshmen.
Friend (v): The verb sense of friend, as in "I friended her on Facebook" became popular around 2005, although, apparently the friend has been used as a verb periodically since the 14th century
Unfriend (v): Doesn't show up until about 2007, allegedly. Apparently, everybody needed two years to figure out that the people they hated in high school are just as bad now as they were then. However, unfriend as a noun meaning enemy has been around since the 13th century, mostly among the Scottish, although it fell into disuse in the 19th century.
App: Computer jargon from 1992, it's short for application.
Edit: I just saw a news story that a couple in Israel named their baby Like, after the Facebook phenomenon Good luck, kid.