Yes, "retweet" is totally a word—so says the Oxford English Dictionary in the new, centennial 12th edition of its Concise English Dictionary, which includes some 400-plus new entries largely drawn from a pool of Internet-related slang and social networking terminology.
At first I was going to ignore this story, but it has since been picked up everywhere from CNN to Rolling Stone to the Hindustan Times. It is indeed the most popular word-related story of the week. Language enthusiasts may feel either a sense of betrayal or relief at the idea that the OED has made the latest slang somehow more "official"—as CBS's Tech Talk blog reported, "Writers and editors no longer have to feel guilty for using words like 'retweet' and 'sexting' in earnest."
But it's all good. The purpose of dictionaries since Samuel Johnson's time (and tome) has been to document the language as it is, not define it (only the words within). And there's nothing wrong with the opportunity to learn new words. Two of my favorites from the list of new entries are words I'd never heard (not surprising, since they're both fashion-related):
mankini: n. (pl. mankinis) a brief one-piece bathing garment for men, with a T-back.
jeggings: pl. n. tight-fitting stretch trousers for women, styled to resemble a pair of denim jeans.
The Concise English Dictionary, first published in 1911, was designed specifically as a working language manual of its time—whatever the time happened to be. As the newest edition's editor, Angus Stevenson, explains:
The editors of the first edition, brothers Henry and Frank Fowler, stated that ‘we admit colloquial, facetious, slang, and vulgar expressions with freedom, merely attaching a cautionary label’. Among the slang words they included were flapper, ‘girl not yet out [in society]’, foozle, ‘do clumsily, bungle, make a mess of’, mag, ‘halfpenny’, piffle, ‘talk or act feebly, trifle’, and potty, ‘trivial, small’.
Sadly, the new edition has no room for tremendous words like brabble ‘paltry noisy quarrel’ and growlery ‘place to growl in, private room, den’ – what we might call a man cave these days. But the preoccupations of today’s Generation Y have opened the door to some equally colourful vocabulary – how about momo, noob, nurdle, and woot?
So those who think the addition of words like "retweet," "sexting," and "mankini" (and even online abbreviations like "LOL" and "OMG") do nothing but foozle the English language don't need to put up such a brabble—they'll probably be gone in a century if not much sooner.