The clash between Lords and Commons, declared the Daily Mail in a leaderette last Wednesday, "could not be more rich in political irony", its point being that it was the Government, not the hereditary peers, who were being undemocratic this time.

Ironic seems to be a favourite among writers for that paper. Ironically, they tell us, Vicky Lee's breast implants have ruined her sex life, and ironically, the countries who send their best footballers abroad have the biggest chance of developing the talent of their youngsters. Ironically, too, we achieved our best results in the Lincoln Tests with our weakest side, says the Mail.

Meanwhile, the Times says how ironic it is that the best hope for oil companies is for the US to attack Iraq, and a facetious columnist in the London Evening Standard illustrates irony by pointing out that Barbara Woodhouse, who spent so much of her life stroking dogs, eventually died of a stroke.

All these examples of the ubiquitous word except the last, which is to do with coincidence, are about something that's unexpected, or would seem to be illogical. But that is not quite what the ancient Greeks meant when they used their word for it, eironeia, which meant "dissembling".

Irony in this Greek sense is a favourite ploy of Socrates, who enjoys leading on some hapless fall-guy with a theory ("How could it be otherwise, Socrates, of course you're right", says the innocent fellow) which Socrates then proceeds to demolish. This is why Plato is about the only philosopher I can think of who is always a pleasure to read. In English, of course, irony is widely taken to mean sarcasm, as used by superior persons as a put-down ("What a clever girl!"), or by critics, say, who want to pan an author ("Lord Archer's scholarly novels").

The connection between this sort of irony and the sort that so intrigues sports writers and political correspondents is clear enough: both are saying that things turn out to be not what they seem. The Greeks had another, more specialised meaning as well, which they called tragic irony, where the actors say apparently innocent things that mean more to the audience (who know the end of the story) than they do to the characters on the stage. The Oedipus legend, as dramatised by Sophocles, is full of such ironies.

Thus sententious Victorian belletrists, who knew their classics, were fond of talking about the irony of fate. Since then the word has lightened up considerably, and any event that seems slightly ludicrous or paradoxical can safely be called ironic. If it does have a tragic element to it, your practised scribbler will make this clear by calling the irony "bitter"; if there's no harm done, the adjective is "gentle".

Ironically as an attached adverb, like hopefully and luckily, is from our own time. Before, it only meant "in an ironical manner". Nowadays one sees it so often that I can't think how we ever managed without it.