This is a significant year for poetic wordplay, as it is the centenary of the Limerick Craze of 1907. That is the year when magazines and newspapers began to run limerick competitions, in which the first four lines of a limerick were given and readers were challenged to supply the fifth line.

Advertisers caught on to the appeal of these competitions, and challenged people to come up with the last line of a limerick plugging' an advertised product.

These contests probably became a craze because huge prizes were offered to winners - such as a freehold house or an income for life. The popularity of the competitions was underlined in 1908, when the Postmaster-General told Parliament that sales of sixpenny postal orders (the usual fee for entering limerick contests) had risen from less than a million to 11 million.

The craze was reflected in a musical play produced by Seymour Hicks at London's Aldwych Theatre in 1907. It included a song called Limericks in which six characters sang a limerick each, including: There was a young lady of Erskine, Who had a remarkable fair skin.

I said to her: "Mabel, You look sweet in your sable."

She said: "I look best in my bear skin."

This is the normal shape of the limerick: a five-line verse with a galloping rhythm, with three feet in lines one, two and five, and two feet in lines three and four, with a rhyme scheme aabba.

But why is it called a limerick? There must be a connection with Limerick in Ireland, and Jean Harrowven's The Limerick Makers claims to have found the origin in an 18th-century group of poets in the village of Croom in County Limerick who delighted in creating five-line verses in the style which later became known as limericks.

The OED says limerick came from convivial parties where nonsense songs were extemporised which were interspersed with the refrain "Will you come up to Limerick?" The OED's earliest example is from 1896, in a letter by Aubrey Beardsley, although the word is also found in Rudyard Kipling's Stalky & Co (1899) which is based on Kipling's experiences at the United Services College between 1878 and 1882.

The verse-form is actually found much earlier - for example, in a 14th-century manuscript which contains this poem: The lion is wonderly strong And full of the wiles of woe; And whether he play, Or take his prey, He cannot do but to slo (i.e. slay).

As a form of nonsense verse, limericks were found in The History of 16 Wonderful Old Women (1820), which included poems like this (which eerily anticipates the workaholic lifestyle of a busy modern mother): There was an old woman in Surrey, Who was morn, noon and night in a hurry; Called her husband a fool, Drove her children to school, The worrying old woman of Surrey.

This book was soon followed by Anecdotes and Adventures of Fifteen Gentlemen, which included this limerick about an Oxfordshire town: There was an old soldier of Bicester Was walking one day with his sister; A bull, with one poke, Tossed her into an oak, Before the old gentleman missed her.

Limericks really became popular when Edward Lear published his Book of Nonsense in 1846. Many of Lear's limericks sound disappointing nowadays, as he often used roughly the same words for the first and last lines, as in this example: There was an old man of the Hague, Whose ideas were excessively vague; He built a balloon To examine the moon, That deluded old man of the Hague.

In my recent article about pronunciation, I mentioned the strange pronunciation of Menzies in the name of the Lib-Dem leader, Menzies Campbell, whose first name is pronounced ming-is. A limerick plays about with this pronunciation: A lively young damsel named Menzies Inquired "Do you know what this thenzies?"

Her aunt, with a gasp, Replied: "It's a wasp, And you're holding the end where the stenzies."

The best limericks deliver an unexpected punchline at the end, as in this limerick submitted to a New Statesman competition: Prince Hamlet thought Uncle a traitor For having it off with his Mater; Revenge Dad or not?

That's the gist of the plot, And he did - nine soliloquies later.

Arnold Bennett said "All I have to say about limericks is that the best ones are entirely unprintable." It is true that many limericks are rude, a tendency which is summed up thus: The limerick's form is complex, Its contents run chiefly to sex, It burgeons with virgins And prurient urgin's And drips with erotic effects.

Of course, rudery makes some limericks unprintable here, but I'm sure this one will only sound rude to someone with an ear for double entendres: There was a young lady of Norway Who hung by her toes in a doorway.

She said to her beau: "Just look at me, Joe, I think I've discovered one more way."

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).