12 idioms with unexpectedly sinister origins including 'blue blood' and 'wreak havoc' - plus phrase meanings

There are many phrases and idioms which we use in our everyday life, perfectly innocently, to help us convey our thoughts and feelings - but without knowing it we could be saying things which have a very dark past. Idioms are groups of words which do not have a meaning which can be determined by the meanings of the individual words.

Below, we explore the meanings of 12 commonly used English phrases and also delve into their rather ominous and disturbing origins. 

Trigger warning: Includes references to  domestic abuse, racism and violence.

To learn even more about the language and etymology, check out our dedicated words and meanings page and also articles such as unusual English phrases explained: meanings and origins of 14 idioms such as ‘break a leg’, also unusual animal-based phrases explained: meanings and origins of 15 idioms such as ‘get off your high horse’ and unusual food and drink phrases explained: meanings and origins of 16 idioms such as ‘piece of cake’.

Blue blood

Meaning: When we talk about someone having blue blood, we are referring to a person who comes from a privileged, wealthy or noble family.

Origin: The phrase is said to have originated in mediaeval Spain and is linked to the rich families of the Castile region from the time. It has a racist connotation. As part of what was described as their ‘pure Gothic’ descent, the family members would say that their pale skin, which made the blueness of their veins visible, showed that they had never married a person from another race.

Wreak havoc

Meaning: This phrase means that an event, or a person, has caused great damage - usually physically, but sometimes metaphorically.

Origin: Havoc comes from the French word “havot”, and was the word shouted to soldiers during the 11th century Norman invasion of Britain when it was time to harm, murder or sexually assault people in a town. 

A baker's dozen

Meaning: A dozen, as we know, is 12 of an item but a baker’s dozen is 13 of the item.

Origin: This is another phrase that dates back to mediaeval times and comes from a threat given to bakers in the Assize of Bread and Ale law that if any of their products weren’t of the correct weight they would lose their hands. To stop this from happening, baker’s would add in an extra item to make sure they couldn’t accidentally sell items which weren’t of the correct weight.

Sold down the river

Meaning: If someone says they feel someone has sold them down the river, they mean they feel that the person has betrayed them particularly for their own personal gain.

Origin: This idiom dates back to the 19th century, when slaves were literally taken up and down the river to be sold to plantation owners.

As pleased as punch

Meaning: If you tell someone you are as pleased as punch what you mean is you are really happy with something.

Origin: The phrase relates to the classic children’s puppets Punch and Judy, which are still enjoyed by families today. Nowadays, a Punch and Judy show is all about slapstick comedy, but when it was first created the show would include beatings and even murder.

Rule of thumb

Meaning: This is a phrase used to mean that something is generally accepted based on previous experience.

Origin: There is some suggestion that between the 17th and 18th century, a thumb was used as a measurement - and there was a law that men would be allowed to beat their wives with a stick no wider than his thumb.

A blockbuster

Meaning: Today, a blockbuster is used to refer to a film which has a big budget and has also made lots of money at the box office.

Origin: Blockbusters were actually bombs used by the Royal Air Force in World War Two.

As mad as a hatter

Meaning: This phrase has a rather difficult meaning. Some people use it to refer, in a loving way, to someone being eccentric. Others do use it as an insult, however, and in these ways it can imply that someone may be suffering from a mental health illness.

Origin: The phrase actually relates to a time between the 18th and 20th century when hat makers would suffer from mercury poisoning, and this would negatively impact their state of mind.

Pulling your leg

Meaning: If someone is pulling your leg this means that they are joking with you. They are following around with you and possibly telling you something which isn’t true, but trying to make you believe that it is true.

Origin: The phrase originates from the 18th and 19th century when thieves would literally pull on people’s legs to pull them to the floor or cause them to become unstable so they could then steal their possessions.

Crocodile tears

Meaning: Someone who cries crocodile tears is said to be shedding tears in an insincere and unconvincing way.

Origin: Another phrase from mediaeval times, this one does actually have a somewhat literal meaning as some people did say that crocodiles would cry after they had killed their human prey.

Cat got your tongue

Meaning: This phrase is used to refer to someone who isn’t speaking, particularly after they have been asked a direct question.

Origin: It’s unclear exactly where this idiom comes from, but none of them are very nice. The earliest use of the phrase apparently came in written form in an American magazine in 1881 where it was said to be a taunt used by children. Some believe it is derived from a mediaeval fear of witches and black cats. Another theory is that the cat refers to cat-o’-nine-tails, a whip used on sailors which would leave them in so much pain they couldn’t speak. A final apparent link is to ancient Egyptian kings who are said to have cut off the tongues of liars and then fed the tongues to their cats. 

Waking up on the wrong side of the bed

Meaning: Someone who woke up on the wrong side of the bed is said to be in a bad mood, especially in the morning.

Origin: The phrase comes from ancient Rome, in a time when people believed in spirits and truly believed that if they got out of bed on the ‘wrong side’ they would have bad luck, but if they got out on the ‘right’ side they would have good luck.