On the evidence before him, the editor, Angus Stevenson, removed about 16,000 hyphens from words in the dictionary. Ice-cream became ice cream, make-over became makeover, and post-modern became postmodern.

Stevenson justified the change by suggesting that informal methods of communication - like e-mails and texting - are squeezing out the hyphen. He added: "People aren't confident about using hyphens any more; they're not really sure what they are for."

I can imagine some people feeling unsettled by the notion that language should change just because some people don't understand it properly. Yet compound nouns have been losing their hyphens for many years. Where people used to write to-day and teen-ager, the accepted forms are now today and teenager.

In fact we can be grateful that some uses (or misuses) of the hyphen have already died out. In Mind the Stop (1958), GV Carey said: "There is (or was until lately) a convention in certain quarters of printing the names of streets etc. as Regent-street', Portland-place', Shaftesbury-avenue', Berkeley-square', and so on." He adds: "There are signs that this irritating practice is beginning to decline."

Carey notes that there are usually three stages in the evolution of connected pairs of words. They start as separate words; then they are hyphenated; and finally become a single word. Lipstick started out as lip stick and then became lip-stick before fusing into one word.

Hyphens still have some important roles to play. The SOED editor agreed that: "There are places where a hyphen is necessary, because you can certainly start to get real ambiguity." An example he gave was: "Twenty-odd people came to the party - or was it twenty odd people?"

There is a real difference between "There are no-parking signs in our street" and "There are no parking signs in our street." The deep-blue sea is not the same as the deep blue sea. And a man-eating shark in an aquarium is different from a man eating shark in a restaurant. My favourite example of ambiguity caused by the lack of a hyphen is "Where is the lost property office?"

Hyphens are also useful to clarify the pronunciation of grouped words. Omitting the hyphen from co-operative makes it look as if it is pronounced KOOP-er-rer=tiv. Is it really safe to remove the hyphens from do-gooder, co-opt, co-worker, get-at-able, or state-of-the-art?

Some groups of words are so long that they would look ridiculous without hyphens. This is certainly the case with long plant-names, like John-go-to-bed-at-noon, kiss-me-at-the-garden-gate, and kiss-me-twice-before-I-rise, which are all in the OED. Omitting the hyphens from place-names like Wath-upon-Dearne or Wells-next-the-sea would surely be the work of a semiimbecile.

The word semiimbecile suggests another valuable use for hyphens: to avoid awkward groupings of letters, as in breast-stroke, pre-eminent, drip-proof, anti-inflation and glow-worm.

Hyphens are also used to link nouns in apposition (i.e. that are connected in sense as well as grammatically), such as actor-manager or city-state, where you are describing a person or thing that is two things simultaneously.

Hyphens are still accepted as the normal way to indicate that a word is divided at the end of a printed line. The 1680 publication called A Treatise of Stops, Points, or Pauses says: "An hyphen . . . is used . . . in words, when a line will not contain the whole word without it be made longer than the rest, which is not convenient."

The end-line hyphen dates back to the Gutenberg Bible of 1455, in which each printed line was the same length, necessitating the division of some words at the end of lines. This practice continues in the large number of publications where the text is "justified" - with straight edges on the right, as well as the left of a block of text.

Of course, this can create its own problems. A recent correspondence in the Guardian pointed out the danger of dividing the word legend into leg-end. Notable can be turned into not-able (or no-table), while fatally can transmute into a fat ally. Probably the most hazardous word to split up is therapist.

Ronald McIntosh's Hyphenation (1990) points out that many faulty word-divisions arise from computer typesetting, which uses ready-made programs. He quotes from the Buenos Aires Herald for July 7, 1989, which had such divisions as sk-ylab, airs-pace, wo-rried and bi-llion, because it was "splitting English with a Spanish-language program." But he notes that the Sunday Times the same year included dubious word-divisions like Europe-ans, stro-ll, brou-ght and ar-eas.

In 1963, the Mariner I spacecraft was launched from Cape Canaveral on a mission to Venus but started flying erratically, and had to be blown up.

A scientist reported: "Somehow a hyphen had been dropped from the guidance program loaded aboard the computer, allowing the flawed signals to command the rocket to veer left and nose down."

Tony Augarde is the author of The Oxford Guide to Word Games (OUP, £14.99) and The Oxford A to Z of Word Games (OUP, £4.99)