Spin doctor, Harry Potter and Hogwarts, Blair babes, Frankenfood, netiquette and velvet divorce - are all words which pepper our language these days. But what do they mean and where do they come from?

The answers lie in a newly-published tome from the Oxford University Press (OUP). The New Oxford Dictionary Of Phrase And Fable has been written to try to demystify and decode our language.

It is not only a dictionary of the past, it also records today's words, phrases, people and places.

The idea for the book had been lingering in the Oxford offices for close on a century.

In 1927, Kenneth Sisam, then head of Oxford University Press, put forward the idea of an Oxford companion to English literature. As Sisam pondered the project further he wanted to include classical, historical and scientific phrases. However, the end result never did include Sisam's recommendations.

But the idea wasn't forgotten and by the late 1990s, OUP resurrected it.

Elizabeth Knowles, editor of the New Oxford Dictionary Of Phrase And Fable, recognises the potential impact of the dictionary. "In many ways I'm glad the idea was shelved in the 1920s. We've been able to start from scratch and use all the resources to pull together the language that we use today. We have never been better placed for an overview," she says.

Knowles and her team have been working on the project solidly for two years, but she believes this gives a shortened view of the work undertaken.

"When people use the dictionary I hope they appreciate that other books have fed into it."

Agreeing to disagree on the definitive dictionary meaning is common practice but more so in this case. Knowles acknowledges this fact. "Every word or phrase has so many ideas and beliefs behind it. It just depends on how much of the story you want to tell," she says.

Many words have been included because their original meaning has been misconstrued over the years.

For example "Lord Lucans" are people who disappear, even momentarily, from a scene - they don't have to be aristocrats.

If a town undergoes an X-Files encounter, it becomes known as "Roswell" - in reference to the reported alien findings in Roswell, Texas, almost 40 years ago.

"Words and phrases have a resonance behind them. They may not have an encyclopaedic definition, but they will serve the context," claims Knowles.

York is frequently referred to in the dictionary. Jorvik is included with its common association with Vikings. "Eboracum is the old name for York. It's second definition is the roman Archbishop signature.

"We also look at the derivation of the Ridings. North Yorkshire has a definite presence in the dictionary," says Knowles. Words often become associated with events and they can never be erased from memory - no matter how many centuries have intervened.

Knowles is keen to point out that Britain's role in the Balkans brought a surprise. "Robin Cook, the Foreign Secretary, accompanied his ethical foreign policy by suggesting the war in Kosovo was a 'just war'. That saying was first written about by medieval theologian St Thomas Aquinas," she claims.

The dictionary also features words you would think had been made up by a five year old. "Spaghettification has nothing to do with Italian food but it's what happens to something that falls into a Black Hole," says Knowles.

"Frankenfood is a word associated with genetically modified foods. You're unlikely to find any other dictionary with these kinds of meanings."

Many commentators may criticise the work claiming it belongs as a Christmas stocking-filler rather than a reference guide to our modern language.

Knowles dismisses such a suggestion. "It's entertaining but also a serious look at an area of language that hasn't been looked at before in any great detail."

The dictionary also includes a range of fascinating lists.

"It's an extra resource that the readers can use. With online technology we have been able to compile the lists instead of trundling through static structures on the written page," adds Knowles.

There is vehement denial that OUP is dumbing down the English language by encouraging the public to use words often regarded as slang.

Knowles says: "There are examples of casual language but this is all part of the organic and creative process. Historical lexicographers, like myself, even look down on what is regarded as the Golden Age of Language. There never is a perfect time."

And for those about to threaten their spouses with a 'velvet divorce' you had better know what it really means. It's an amicable split between two parties and was first coined in relation to the non-violent break-up of Czechoslovakia in 1992, which divided into the Czech Republic and Slovakia.

* The New Oxford Dictionary Of Phrase And Fable is published by Oxford University Press, at £25.