Etymology, the study of the origin of words, can be fascinating.

Since language is constantly evolving, the meaning of many phrases has changed over time, sometimes obfuscating sexist, racist, and violent pasts.

These are seven everyday phrases with surprisingly sinister* origins.

1. Baker's Dozen

Making perfectly even loaves of bread every time was impossible in medieval England. Wikimedia Commons In 13th-century Britain, under the reign of Henry III, a statute called the Assize of Bread and Ale stated that bakers could lose their hands for selling their customers "lighter" bread, or loaves of lesser quality.

Because it was hard to make all loaves exactly the same, bakers would throw in a small piece of extra bread when they sold a loaf. If a customer ordered 12 loaves, the baker would add an entire "vantage" loaf to make a "baker's dozen," just to make sure he wasn't accused of “short-weighting” the buyer.

The practice became so common that it was even written into the guild codes of the Worshipful Company of Bakers in London.

2. Blue Blood

Today, anyone from an old or aristocratic family is referred to as a “blue blood.” But the term has a racist past.

Blue blood comes from the Spanish phrase "sangre azul," or "blue blood." Aristocratic Castile families coined the term after Spain conquered Moorish lands in 1834 to refer to the fact that they were “uncontaminated” by Moorish or Jewish blood, because their complexions were fair, which caused their blue veins to stand out.

The racist undertones may be gone, but the classist notion persists.

3. As Pleased As Punch

Punch the puppet is a creepy serial killer. welshmackem/Flickr When you tell someone you’re “as pleased as punch,” it usually means you’re satisfied. But this phrase is rather gruesome.

The punch does not refer to a beverage but to the children’s puppets Punch and Judy, whose repertoire included wife beating, baby squashing, and murder.

The puppet shows became a staple in England during the late 1600s. The plot line generally followed the same theme: Something angered Punch and he would go on a killing spree, murdering everyone with his “slapstick.” Usually Punch would kill his child, then his hysterical wife, Judy, then any authority figure — policeman, doctor, concerned citizen — who came to investigate. He would laugh and say "That's the way to do it!" after each killing.

It’s pretty messed up, but the Brits still aren’t tired of Punch and Judy after nearly 400 years.

4. Wreak Havoc

“To wreak havoc” means to create chaos and refers to a whole variety of behaviors. But in its original usage, havoc referred to theft, murder, and rape.

Havoc was an Anglo-Norman battlefield cry that meant soldiers could bring unlimited slaughter, destruction, and plunder upon the land. Under the reign of Richard II, in the 14th century, the cry was outlawed, and those who raised or answered it were sentenced to beheading.

5. Meeting A Deadline

A re-creation of Andersonville Prison. You can see the pigeon roost and wooden "dead-line" fence. Mark D L/Flickr Today, having to “meet a deadline” might evoke dread, but that's nothing compared to the original meaning of the phrase.

The “dead-line” was the term for a literal line at Andersonville Prison, a Confederate prison for Union soldiers during the Civil War. The prison, which existed for only 14 months, was built to accommodate a maximum of 10,000 people in a stockade surrounded by tall pine logs.

Within that compound was another fence surrounding the prisoners that was called the "dead-line." It was built 20 feet away from the surrounding walls to stop anyone from climbing over or tunneling under, and sentries were posted in pigeon roosts to shoot any prisoner who crossed or touched the fence.

To make matters worse, there was massive overcrowding, causing nearly a third of all the prisoners who were sent there to die from poor sanitation, malnutrition, disease, overcrowding, and exposure to the elements.

6. A Blockbuster

Today, a “blockbuster” is a massive commercial hit. But the term used to refer to actual "block busters" — bombs that blew up streets during World War II.

British block-buster bombs, or “cookies,” used by the British Royal Air Force were basically huge cylinders (some 4,000 pounds or larger) filled with explosives that could cause massive damage to buildings.

The term took an entertainment tilt almost 10 years after the brutal war, in 1957.

7. Bulldozer

The 1876 presidential election was highly controversial. The results for four states were disputed, and a final tally of votes showed Democratic candidate Samuel Tilden with approximately 250,000 more popular votes than Republican candidate Rutherford B. Hayes, though Hayes ended up with one more electoral vote. Ultimately, President Hayes was elected. Wikimedia Commons “To bulldoze” someone means to bully or coerce them. And while this isn’t the nicest phrase, it pales in comparison to its origins.

An iteration of the phrase first appeared in 1876. “Bull dose” meant to beat someone in an extremely cruel and brutal way, or to give a “dose” of lashing and whipping like one would whip a bull.

The term was quickly appropriated for racists who violently terrorized African-Americans after the Civil War in the South, particularly Southern Democrats who intimidated black voters from voting Republican during the chaotic 1876 U.S. presidential election. By 1880, bulldoze was being used as a verb.

When a machine was finally invented that used brute force to push over or through any obstacle, it was named a bulldozer.

*BONUS: Sinister

The word "sinister" also has an interesting past. It derives from the Latin word "sinister," which meant left or on the left side. In many languages — from Bavarian to Irish — the word for left-handed people also meant "crooked," "deficient," "weakest," and so on. In English, the word "left" comes from the Anglo-Saxon word "lyft," which means "weak" or "broken."

By the 15th century in England, left-handedness had evolved to mean "evil" and was sometimes seen as a mark of the devil. It was said that witches used their left hands to curse their marks.

Because of its dark meaning, left-handed people were forced to switch hands to avoid the stigma. Of course today, most cultures acknowledge that left-handed people are no more sinister than the rest of us, and in fact some of the world's greatest thinkers have been left-handed, like Leonardo da Vinci and Benjamin Franklin.