The New Oxford American Dictionary has named “unfriend” – as in deleting someone as a friend on a social network such as Facebook – its word of the year.

Oxford University Press USA, in a blog post, said “unfriend”, a verb, had beaten netbook, sexting, paywall, birther and death panel for the honour.

“Unfriend has real lex-appeal,” said Christine Lindberg, senior lexicographer for Oxford’s US dictionary program.

“It has both currency and potential longevity,” she said. “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.”

Previous words of the year include carbon neutral, locavore and hypermiling.

Locavores are people who eat locally grown food while hypermilers modify their cars and driving techniques to maximise petrol mileage.