The first casualty of war is language. wave upon wave of euphemisms, neologisms and fresh slang come marching into the dictionary at times of conflict. Wars in Iraq and Afghanistan have popularised terms such as shock and awe, green zones, friendly fire and collateral damage, military-speak for killing civilians. Such words are the equivalent of armies of occupation: once installed in the lexicon, they never leave.

But war is also an astonishing engine for creating new words and phrases. On the battlefield soldiers are thrust into new situations that must be put into words, they encounter sights and languages to be absorbed and adapted into their own, while new technologies and tactics demand new terminologies.

Mostly, however, soldiers are bored, sitting around for long hours passing the time: countless words have their origins in military chat, including the word “chat”. A chat was a slang word for louse, widely used by British soldiers in the First World War. In quiet moments on the Western Front, the men would sit around picking lice out of their uniforms and talking, an activity that became known as “crumbing up” or “chatting”.

As Graeme Donald demonstrates in his new compendium of war-words, Fighting Talk (Osprey, £9.99, offer £9.49 inc p&p from 0870 1608080), some of the most benign words have the bloodiest origins. Mayonnaise, for example, was born out of bloodshed and near-starvation. In 1756, French forces under the Duc de Richelieu finally ousted the British from Port Mahon, on the island of Menorca. But the siege had lasted so long that the Duke's chef had few ingredients left with which to furnish the victory table: he did his best and whipped up a basic sauce from eggs and oil, which he called “Mahonaise”.

This seems like an ideal word recipe: take one obscure Carthaginian general, a forgotten British defeat and an inventive French chef. Stir together and leave to set.

Morris dancing, the much-mocked activity involving grown-up men wearing funny hats and knee-bells, was once a thrillingly dangerous martial ritual brought to Britain in the 14th century by John Gaunt. On his Spanish expeditions, John of Gaunt had witnessed a Moorish sword dance of such extreme violence that one mistake could deprive a dancer of a limb or head. (Morris is derived from the Moorish word “Morisco”.) Imported to Britain, the dance was gradually ritualised and rendered safe.

Even the deadline to which I am writing this column has a brutal origin. The first deadline was drawn around the Confederate prison camp at Andersonville (now Fort Sumter) in Georgia. It was a light fence, 4ft high and about 25ft from the edge of the stockade wall: any Yankee prisoner crossing the line was liable to be shot dead by sentries, on the orders of the exceptionally nasty prison governor, Heinrich Hartmann Wirz, a Swiss mercenary.

The trial of Wirz after the Civil War (he was executed in 1865) brought the term “deadline” into common parlance and journalists, tax-payers and others have been scrambling to meet the damn things ever since.

Squaddies have a particular knack for inventing new words to describe the enemy, their officers, and their hosts. British troops in the Falklands in 1982 referred to local inhabitants as “Bennies”, after the faintly dim character in the television series Crossroads. In reply, the Falkland Islanders called their liberators “Whennies”, since all their anecdotes tended to start with the words “When I was in Germany/Afghanistan/Aldershot etc ...” Senior officers attempted to damp down the word war by banning the word “Bennies”, so the troops began calling the Falkland Islanders “Bubs”, an acronym for “bloody ungrateful bastard”; when that, too, was banned, they resorted to calling them “Stills”, short for “still bloody ungrateful bastards”. And “bastard”, too, springs etymologically from wartime. A “bast” was a species of pack-saddle used in the baggage-trains that followed medieval armies. On the march, this saddle could be spread out to form a sort of rustic bed. A child produced on top of one of these in the middle of a war was likely to be illegitimate, hence bastard, which just goes to show that words can be conceived in the most unlikely and uncomfortable places.

Word of the week: post-turtle

A 75-year-old Texas rancher recently explained this term to a country doctor. The conversation turned to the US election, and Sarah Palin's vice-presidential candidacy, and the old rancher observed: “Well, ya know, Palin is a post-turtle.” The bemused doctor asked what a post-turtle was, and the old man replied: “When you're driving down a country road and you come across a fence post with a turtle balanced on top, that's a post-turtle.” The rancher continued: “You know she didn't get up there by herself, she doesn't belong up there, she doesn't know what to do while she is up there, and you just wonder what kind of dumb ass put her up there to begin with.”

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