It’s by no means unusual for words to change their meaning over time. But thanks to the twists and turns of language – and the convoluted history of English, in particular – some words end up quite a distance from where they began, as the following bizarre etymological stories illustrate.

1. A blockbuster was originally a bomb

In some instances, the original meaning of a word might be hiding in plain sight, and this is one of them: a blockbuster is literally a bomb large enough to destroy an entire block of buildings. In this sense, the first blockbusters were produced by the RAF during the second word war, the very earliest of which – weighing an impressive 4,000lb – was dropped on the German city of Emden during an air raid in March 1941. The wartime press was quick to pounce on the nickname “blockbuster”, and soon it was being used figuratively to describe anything and everything that had an impressive or devastating effect. The military connotations gradually disappeared after the war, leaving us with the word we use today.

2. Girl was originally a girl or boy

When Geoffrey Chaucer wrote of the “young girls of the diocese” in the prologue to the Canterbury Tales in the late 1300s, he wasn’t just talking about young women. Back when the word “girl” first appeared in the language, in the Middle English period, it was used to mean “child”, regardless of the gender of the child in question. That didn’t begin to change until the early 15th century, when the word “boy” – thought to have been borrowed into English from French around a century earlier as another name for a slave, or a man of lowly birth – began to be used more generally for any young man. As boy encroached on its meaning, girl was forced to change or else risk disappearing from the language altogether.

3. A bimbo was originally a man

Bizarrely, bimbo is another word to have changed its sex. Derived from an Italian word for a baby boy, when it first emerged in American slang around the turn of the 20th century, it referred to a menacing, brutish bully (perhaps a reference to a baby’s equally stocky, thickset physique) or a dolt. It didn’t take too long for things to change, however, as in 1920 a song was written for a Broadway revue entitled My Little Bimbo Down On The Bamboo Isle, which referred not to a brutish man, but to a beautiful, voluptuous woman. Precisely what instigated the change is unclear, although one theory suggests that both muscle-bound heavies and voluptuous women both risk being admired more for their appearance than anything else. No matter what inspired it, the term bimbo came to be all but exclusively attached to women, to the extent that an exclusively male equivalent, himbo, had to be invented in the late 80s to redress the balance.

4. Alcohol was originally eyeshadow

The ancient Egyptians made their distinctive jet-black eyeshadow out of the mineral stibnite, which was crushed and heated to produce a fine dust that could then be mixed with animal grease to make a cosmetic paste. The name of this paste was al-kohl, a term derived from an ancient Arabic name meaning “the stain” or “the paint”. Alchemists and scientists of the European middle ages then picked up this term from their Arabic-origin textbooks, and began applying it to all kinds of other substances that could be produced through similar means – which included the distillation of wine to form its purest essence, ultimately given the name “alcohol”.

Kohl-eyed: Elizabeth Taylor as Cleopatra in the 1963 film. Photograph: Everett/Rex/Shutterstock

5. A cloud was originally a rock

The Old English word from which our modern word “cloud” derives, clud, didn’t mean “cloud” at all but rather “rock” or “mountain”; through it, cloud is actually a distant relative of words like clot and clod. But because enormous grey rainclouds can appear (albeit with a little imagination) like enormous grey masses of stone, it’s thought that these two meanings became confused, and eventually the meteorological sense of the word won out to give us the word we use today.

6. A cupboard was originally a table

A cupboard, quite literally, was originally just a board on which to place your cups. Or put another way, a cupboard was originally a table – as was a sideboard, incidentally (albeit one placed specifically at the side of a room). No one is entirely sure why, but by the early 16th century that meaning had begun to disappear from the language, and a cupboard was no longer a tabletop on which to use or display one’s crockery, but a covered recess in which to store it. By the 17th century, people were beginning to store food in cupboards (to cry “cupboard” meant “to crave food” in the late 1600s), while the author Wilkie Collins was the first to find a “skeleton in his cupboard” (an expression later changed to closet) in 1859.

7. A handicap was originally a fair exchange

There’s a pernicious old myth that claims the word handicap refers to beggars, wounded by war and so unable to work, relying on begging with their upturned caps in their hands just to make ends meet. The true origin of the word handicap is much more bizarre: originally, it referred to a means of securing a fair deal once popular among medieval traders, in which two parties offering goods for exchange would call upon a neutral third party, or umpire, to oversee the deal. The umpire would assess the value of the goods involved, and give the owner of the less valuable goods a cash figure that they would have to add to the deal to make it fair.

Both traders would then take a small gratuity or a token amount of cash in their hands, and go to place their hand inside the umpire’s cap. If both agreed to the deal, they would drop the cash into the cap (which the umpire would get to keep, as his fee for securing a fair deal) and the deal would be done; if neither (or just one) trader agreed, the umpire would get nothing and no deal would go ahead. It was from this image of the value of individual items being assessed and compared that the first handicap horse races were introduced. The notion of the better horses in a handicap race being intentionally weighted down meant the word handicap eventually came to mean a hindrance or disability.

8. A meerkat was originally a monkey

The name “meerkat” probably has its origins in markata, a Sanskrit word meaning “ape”. This word was then picked up from central Asia by European explorers and traders in the early middle ages who altered it to meerkat, a Dutch-inspired word essentially meaning “sea-cat”. In this sense, the word probably became little more than a placeholder for any four-legged animal that originated overseas, and was ultimately first used in print in 1598 by a Dutch merchant sailor to refer to a South American monkey, rather than an endearing African mongoose.

9. A moment was once precisely 90 seconds

“Moment” has its origins in the Latin word for movement, momentum, and as a general word for a short period of time probably refers to the slightest movement of the hands of a clock. But, oddly, the word “moment” wasn’t always so general: in the medieval period, the 24 hours of the day were each divided into four 15-minute segments known as points, each of which in turn was divided into 10 shorter segments known as moments. So next time someone says they’re going to be a moment, remind them that by definition they’re going to be precisely one fortieth of an hour – or exactly 90 seconds.

10. A treadmill was originally a prison punishment

It might come as little surprise to learn there’s a connection between gym equipment and hard labour punishments doled out in Victorian prisons, but the fact is that the original treadmill was an enormous man-powered mill used for tasks such as crushing rocks and grinding grain.

Invented by a 19th-century engineer named Sir William Cubitt, the original treadmill was essentially a never-ending staircase – a wheel of steps encircling a vast cylinder attached to a millstone, on which convicts could be gainfully employed for many hours a day; famously, Oscar Wilde was made to toil away on the treadmill during his imprisonment in Reading jail in 1895. Prison reform after the turn of last century made Cubitt’s treadmill a thing of the past, but the term was resurrected in the 50s during the post-war vogue for health and fitness, and was applied to an item of gym equipment likewise comprised of a (seemingly endless) foot-powered belt.

Paul Anthony Jones’s The Accidental Dictionary is published by Elliott & Thompson, £12.99