
The Urban Dictionary, a user-generated online archive of American slang, includes multiple entries for both "defriend" and "unfriend."
One of the more popular entries for "unfriend" describes it like this: "Compulsive people prune their friend list periodically, removing people that they no longer have contact with. More often though, unfriending is only done when a particular friend's updates and self-promotions become so annoying that you can no longer stand hearing about them."
The entries for "defriend" are nearly identical.
Also defining it as the action of removing someone from a social networking site's "friend" list, one entry says, "Doing this is often seen as a passive-aggressive move, telling the person without telling them that you no longer want to be friends. It's also commonly a response to drama. Defriending someone often causes more drama. There are sometimes valid reasons for doing this."
Jillian Quint, 27, an assistant editor at Ballantine Books in New York City, said she thinks "defriend" is more accurate.
"Unfriend… implies a complete lack -- that you are absolutely not friends," she said. "Defriend implies that you were once friends."
She said she's heard both but thought the word "defriend" was already in parlance.
"Defriend seems to apply more to the action. Unfriend seems to apply more to the state of being," she said.
But despite the continuing debate on and offline, Oxford said the decision was cut and dried.
"Unfriend was chosen because it's much more common than defriend," Lauren Appelwick, a publicist with Oxford University Press, Inc., told ABCNews.com.
Though she couldn't elaborate on Oxford's methodology, she said the department responsible for tracking the use and evolution of language is very good at monitoring language trends.
"It's funny because there seem to be little clusters of people who have never heard the word "unfriend," she said, but added that research indicated that "unfriend is far, far more popular."
In announcing the word of the year, Oxford's Lindbery said, "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!)."