8 Common Phrases with Surprisingly Dark Origins

Many English speakers don’t give much thought to the idioms they use on a regular basis. Some common sayings have silly backstories, while others are more disturbing than they seem out of context. From poisoning to warfare, here are the dark origins behind everyday phrases that may be part of your vocabulary.

1. Mad as a Hatter

The phrase mad as a hatter may sound whimsical, but it refers to a serious medical condition that once plagued the hatmaking industry. In the 18th and 19th centuries, fur felt (which is more durable and lightweight than wool felt) for hats was made by treating animal pelts with mercury nitrate. Workers exposed to this toxic substance over time developed symptoms such as tremors, speech problems, hallucinations, and mental and emotional instability. The popularity of the phrase mad as a hatter shows how widespread the ailments were, but mercury continued to be used in hatmaking into the 20th century. The U.S. officially banned it from felt production in the 1940s.

2. Riding Shotgun

Today, riding shotgun simply means sitting in the passenger seat of a vehicle, but according to How Stuff Works, that spot came with big responsibilities on stagecoaches in the Wild West. If a coach was transporting something valuable, the person who sat beside the driver might be tasked with fending off potential thieves and wild animals with a literal shotgun. Although the concept originated in the Old West, the phrase riding shotgun itself wasn’t used widely until the 20th century—after occasionally popping up in newspapers, then often in Hollywood Westerns, until it got its less-violent interpretation that applies to car travel.

3. Take It With a Grain of Salt

Today, if someone tells you to take information “with a grain of salt,” you should be skeptical of its veracity. The origin of the phrase is a bit murky: According to one theory, the phrase was meant literally when it appeared in a disturbing context in 77 CE. Greek writer Pliny the Elder included the words “addito salis grano” in his translation of an antidote for poison. The passage from his treatise The Natural History reads:

"Take two dried walnuts, two figs and twenty leaves of rue; pound them all together, with the addition of a grain of salt; if a person takes this mixture fasting, he will be proof against all poisons for that day."

This is one possible explanation for why we say to take something "with a grain of salt," but experts disagree on when the phrase as we know it today first appeared. According to Merriam-Webster, grain of salt was first used in its modern, idiomatic sense in 1647.

4. Drinking the Kool-Aid

The origin of this saying, meaning "following the crowd," comes from the Jonestown massacre. On November 18, 1978, over 900 members of the Peoples Temple movement died in a mass suicide event that involved a fruit-flavored beverage laced with cyanide and other drugs. The murder-suicide orchestrated by cult leader Jim Jones is considered one of the deadliest non-natural catastrophes in U.S. history. (Though the tragedy took place in Guyana, the majority of the victims were American citizens.)

Today, drinking the Kool-Aid can be applied to anyone who blindly embraces a group or trend, especially if it's to their detriment, but there are a couple of reasons you should rethink using the phrase. In addition to being in poor taste, it's not accurate: The victims at Jonestown actually drank an off-brand powdered drink called Flavor Aid, leading to one of the more unfortunate cases of brand name generalization of all time.

5. Meet a Deadline

The word deadline was meant to be taken literally in the 19th century. During the Civil War, a dead line marked the boundary surrounding a prison—sometimes in the form of a ditch or line in the dirt. Captive soldiers who crossed it risked getting shot. After the war, the term took on less serious implications. Coming up against a deadline isn’t exactly a desirable situation today, but you won’t be killed for handing in your term paper late.

6. Bite the Bullet

Someone is usually told to "bite the bullet" before pushing through something unpleasant. Centuries ago, that something unpleasant was considerably more painful than a bothersome chore or inconvenient meeting. According to one theory, the phrase originated with wounded soldiers undergoing surgery on the battlefield without anesthesia; they were given something solid but malleable to bite down on, like a bullet, which prevented them from crying out in pain or biting their tongues. But some have cast doubt on this theory, pointing to a lack of evidence and the fact that surgeons had leather straps in their kits for patients to bite down on.

An alternate origin story applies the same idea to victims of whipping. In the definition of the slang term nightingale in his 1796 book A Classical Dictionary of the Vulgar Tongue, English lexicographer Francis Grose mentions soldiers who would "chew a bullet" while being flogged:

"A soldier who, as the term is, sings out at the halberts. It is a point of honour in some regiments, among the grenadiers, never to cry out, or become nightingales, whilst under the discipline of the cat of nine tails; to avoid which, they chew a bullet."

Punishments by flogging and surgeries without anesthesia are thankfully less common today, but the saying has stuck around.

7. Hot Shot

A hot shot is a (typically young) person who has an annoying habit of flaunting their success. Originally, the term described a special type of cannonball hurled at enemies. Hot shots were heated up on open grates or in furnaces for the purpose of setting opposing ships on fire. Because the red-hot iron balls could ignite gunpowder easily, they had to be handled with extreme care and skill.

8. Show Your True Colors

The phrase show your true colors originated on the high seas. To gain the trust of an enemy vessel, warships used to take down their flag and fly the colors of a different country—also known as false colors. Once they came within firing range, the disguised ship would switch flags, thus “showing its true colors.” Pirate ships were known to use the same trick to get close to the vessels they targeted. Now the same expression is applied to people who act in deceitful ways to get what they want before revealing their true nature.