BBC correspondent Bernard Wilson: Advice on grammar is most controversial

The New Oxford Dictionary of English has taken 30 editors and 60 worldwide consultants six years and £3m to compile.

The Oxford University Press started from scratch to redefine every word in the language and its contemporary meaning from scratch for the dictionary.

Instants is also recognised

The result is a new dictionary, billed as the most important English dictionary for 100 years, which contains 350,000 words, but contains fewer meanings for individual words than previous dictionaries.

That is because, using new psychological theories on how our brains use language, the dictionary identifies a small number of core meanings for each word.

As well as including more than 2,000 new words - including instants, off message and road rage - the dictionary also gives advice on political correctness.

Advice on the usage of words is given, such as how the use of black, white or person of colour is acceptable, but not spinster, squaw and harelip.

The dictionary is the first written from scratch by the Oxford University Press in more than 70 years and was compiled using the latest computer technology to analyse how the meaning of words has changed.

Blairite and off message are included

Oxford University Press spokeswoman Helen McManners said: "We started compiling it six years ago. It was an absolutely monumental task."

Using written English in novels, reference books, magazines, newspapers and transcripts of the spoken word a 'corpus evidence' was created so every word in the language could be analysed for its different meanings.

Each time a word occurs it was fed into a database along with a 'tag' defining its meaning in that context so when a lexicographer defined it they could call up the ways it is used in the corpus evidence.

Ms McManners said: "What this means is that 20 years worth of reading can be scanned in seconds to see exactly how that word is used and what it means."

The dictionary team drew on the British National Corpus, containing 100 million words, the 40 million-word American Corpus, the 44 million-word Oxford Historical Corpus, and 43 million words of citations collected by the Oxford World Reading programme.

• e-mail: talkingpoint@bbc.co.uk