The online launch of the Oxford English Dictionary is the most significant step so far in its migration from print to digital media. First published in 1928, the dictionary went through a second edition and several supplements before being released on CD-Rom in 1992.

The recent second CD-Rom edition with its revised browser-style interface (Version 2.0, pound;293 inc VAT for two CD-Roms, reviewed in TES Online on February 11) was hardly an unqualified success. Pricey, slow, and - worst of all for schools - non-networkable, it suggested that Oxford University Press was trading on past glories. And with a word database derived from the 1989 edition it seems outdated next to its rivals.

The online OED is a vast improvement. The interface has been significantly tweaked in small but important ways. Word searches can now be activated directly from the query box; text can be copied and pasted into Word documents and then reformatted; complete word entries can be printed out. Subscribers can e-mail the URL (web page address) of any word in the dictionary to friends or colleagues and these entries can be accessed by the recipient for three days. Teachers and parents, take note - any word. The classroom potential for such cyber-mischief is self-evident.

At the heart of the software is a powerful and versatile search engine. The default command, “simple search”, lets users enter a word into the query box and will return a number of hits. Typing in an asterisk before or after a group of letters (wild card search) will call up all the words with those letters: *phobia, for instance, yields 115 entries including the exotic ailurophobia, “a morbid fear of cats”.

A more sophisticated search option allows searches by author, date, quotation, definition and - for those who enjoy serendipity - proximity. The proximity search looks for a term that is defined by two specified words; type in “teeth” and “grinding” and you get “bruxism: Involuntary or unconscious grinding or clenching of the teeth, esp. during sleep”.

It’s very fast. A full text search for “the” unearthed 1,591,320 hits in five seconds. The OED site is hosted by HighWire Press at Stanford University, California, which has high-speed access to the public Internet and connects to an overseas network for improved performance in Europe, Asia and Australasia.

The most exciting news, however, is that the online dictionary signals the beginning of an overhaul of the entire OED, the first since its original completion. The pound;35m project is expected to last until 2010 and could double the length of the dictionary, taking the number of words and phrases to 1.3 million, with 4,000 new and revised entries to be added this year.

Current editorial policy, for historical reasons too complicated to explain here, is to work through the dictionary alphabetically starting at the letter M, but chief OED editor John Simpsn has indicated that some new words may be added and interspersed throughout the text later this year; a good move, if only to avoid the startling irony of an online dictionary that cannot keep up with its own medium. So far there are no entries for “Internet” or “intranet” though “cyberspace” is there. “Online” is described in the older sense of a computer being connected to a network and, even more bizarre, W.W.W. in this edition does not stand for World Wide Web, but for World Weather Watch.

The first revised section, M-MAH, contains more than 200 new words and meanings and reflects the “many Englishes”, that enrich our language. From Australia we have “maginnis” (a wrestling hold), from the United States “mack” (a man who is sexually successful with women) and from the UK “mad cow disease”.

One of the most important functions of the OED is in establishing the provenance and history of words. Hence, “skyscraper”: “a triangular sky sail; 1794”, “a high-standing horse; 1789” and “a very tall man; 1857”. The current use of the word, “a high building of many storeys” is not recorded until 1883.

Similarly, one of the current uses of “rap” as in conversation, talk, chat, was first recorded in Yorkshire, more than a century ago (“Let’s ‘ev a pipe an’ a bit o’ rap”; 1898 R Blakeborough).

Going online presents a great opportunity to escape the tyranny of text. Language may be the most exact tool for expressing abstract concepts such as “love” or “truth” but the sensate world is often best comprehended through the senses. How better to accurately describe a parabola, parallelogram or cube than with an image? How better to explain key modulation, dissonance or syncopation than with sound?

One obvious and welcome addition would be the inclusion of sound files. Lexicographers may have no trouble with that arcane symbolism otherwise known as the international phonetic alphabet but a great many users - particularly in schools - would surely rather click on a word and hear it pronounced.

the problem is presumably not software technology (sound files have been included in the Collins Cobuild dictionary since 1995) but the size of the lexicon. Doctor Johnson, in one of his spats with Boswell (The Life of Samuel Johnson by James Boswell, 1791) knew which method he preferred (Boswell: “But, Sir, we want marks to ascertain the pronunciation of the vowels. Sheridan, I believe, has finished such a work.” Johnson: “Why, Sir, consider how much easier it is to learn a language by the ear, than by any marks”).

John Simpson regards the OED Online as the universal dictionary of the future. This edition will, he believes, “bring a bigger and clearer picture to more people than ever.” With an overarching revision well under way and a medium that has the potential truly to reflect and accommodate this living, vibrant language, and instil a love of it in Internet-friendly young people, he could well be right.

www.oed.com: the home page of the Oxford English Dictionary with hypertext links to What’s New, Word of the Day and About OED www.oed.comtour : excellent online tour of the OED