During the final hours of Napoleon's defeat at Waterloo, one of Bonaparte's generals, a certain Cambronne, found himself hopelessly outnumbered by the enemy. Asked to surrender, the general is said to have raised his sabre and hurled across the barricades a single, defiant syllable: Merde!

This was most likely the sound left ringing in the ears of his men as they ate Prussian lead. With one celebrated utterance, that five-letter word—known ever since as the mot de Cambronne—became the quintessential French oath. It is, however, just one among scores of delicious curses that make up the lexicon of Gallic naughty words—words that, once mastered, can provide a lifetime of service.