The Instant Expert: Best keep your wig on

This week Elizabeth Pearson delves into the origins of some common idiomatic sayings.

THE BASICS As winter ends and spring arrives, you may notice that the odd colleague is behaving as mad as a March hare.

EXCUSE ME, WHAT WAS THAT? You know, mad, like crazy. It's an idiom.

WELL, WHAT DOES IT MEAN? During their mating season, hares behave excitedly: they box each other and bound about, not concentrating on other, more sedate business. This phrase is a short cut, a verbal tic - it means more than it says. It's been around for years.

REALLY? SINCE WHEN? Since the 16th century. Notably, it was included in John Heywood's 1546 collection, A dialogue conteinyng the nomber in effect of all the prouerbes in the Englishe tongue.

OH, SOUNDS LIKE A GOOD READ? ANY MORE GOOD ONES IN IT? Quite a few. You'll have heard of "Don't look a gift horse in the mouth", meaning don't be ungrateful. As a horse's worth was determined by its age (calculated by looking at the teeth), checking out the mouth would be seen as a cynical attempt to ascertain the value of the nag rather than just happily receiving a gift.

ARE THERE MANY ABOUT ANIMALS? Indeed there are. Humans have always had a symbiotic relationship with our furry and not so furry friends, which has enriched our language. Aesop, the Greek writer (620 BC-564 BC), featured animals in many a fable. "A wolf in sheep's clothing" serves as a warning to not trust someone who is pretending to be harmless while being anything but. This ancient story, which crosses many cultures, was in circulation in the Middle East when the Bible was recorded. It first appeared in print in Caxton's translation of 1484.

WOW, THAT'S OLD. WHAT OTHERS DO YOU HAVE? Well, from the same stable (geddit?) there's "the straw that broke the camel's back". From an Arabic proverb, it refers to how the addition of the smallest burden can make the load unbearable. Despite the desert feel, it was first recorded in the mid-17th century and became more common after Dickens used it in the 19th century. Or "whale of a time", which was American slang from around the start of the last century. Basically, the blue whale is the biggest creature on earth, so having a whale of something is having a rather large amount of it.

YOU'RE ON A ROLL NOW Thank you. Need a phrase for when something is annoying you intensely? How about "get your goat"? Goats used to be placed among racehorses before a race to keep them calm. Therefore, if you wanted to scupper your rival's chances of having a winner, you nabbed the goat, thus unsettling the horse so that it would run badly.

BAD FORM, THAT Yes, and probably performed by a "black sheep", a colourful way of describing the ne'er-do-well in the family, which has been around since the 18th century, first appearing in the British comedy A Man of the World by Charles Macklin (1786). A black sheep posed a practical problem as the fleece couldn't be dyed, so it had a lower market value.

ANY MYSTERIES? No one is sure about "raining cats and dogs", an idiom you wouldn't often encounter in the Middle East. Although some creatures, such as birds, have been known to fall from the sky, this, of course, is not a literal expression. It has many purported origins, ranging from the mythical dogs of Odin and associated with storms, to a corruption of catadupe, a French word (of Greek origin) meaning waterfall. However, the most likely explanation is that, before proper drainage systems, animal carcasses were often washed along with other debris after a heavy rain.

Three idioms that sail along

The original speakers of English were the seafaring peoples of the British Isles. Thus, the salty sayings of sea dogs of the 18th and 19th centuries entered the language. Here are three examples:

ON THE FIDDLE (DEFRAUDING) Sailors' plates were square with a raised rim around the edge, known as the fiddle. The fiddle stopped food from slipping, and also served as a measure for what sailors were allocated. If a helping touched the edge - therefore "on the fiddle" - a sailor was said to be fiddling, or depriving another, which was punishable by flogging.

SHOW YOUR TRUE COLOURS (REVEAL YOURSELF) Ships' flags are called colours, and flying them helps identify a ship. If a captain wanted to confuse an enemy, the flag of another nation was flown until battle, when etiquette ruled that the ship hoist its true colours.

BITTER END (TO THE LAST, WHATEVER IT TAKES) Anchor cables were attached to posts on decks, which were called bitts. The end of an anchor cable secured to the bitts was the bitter end. In terrible weather when the anchor dragged, cable was fed out until the bitter end.