Cobble together—in your head, please, particularly if there are children around—a list of the most offensive words and phrases you can think of. Chances are, it's full of the usual suspects: F-words and a whole lot of S-words, right? But here's the thing: Your list is missing quite a few offensive phrases. And we're sorry to report that it's a good bet you use them a lot.

For instance, did you know that the common phrase "basket case" comes from a saying used in World War I to describe quadriplegics? Or that "rule of thumb" has an insidiously violent origin? (And we're sure most parents aren't aware that "fuzzy wuzzy" was a racist term before he was the protagonist of a harmless child's rhyme.) Before you accidentally hurl an insult without even realizing, read up on these 20 offensive words and phrases. And for more expressions you should never utter, check out the Common Phrases That You Didn't Know Have Racist Origins.

Sure, we've all heard "peanut gallery" used to describe harsh critics—usually ones with little knowledge of a situation—but the phrase originally refers to a section in Vaudeville-era theaters. It was usually the area with the worst seats in the house, where Black people were forced to sit.

To many people, calling someone "spastic" is just as offensive as calling someone the R-word. The stigma stems from the word's association with cerebral palsy, a disease that was once referred to as spastic paralysis. And for more words you haven't heard in a while, check out the 100 Slang Terms From the 20th Century No One Uses Anymore.

The word "hooligans" derives from a family of cartoon characters of the same name. In the 19th century, the Hooligans were a family of Irish immigrants struggling to fit in in London. Not only were the cartoons racist, but they also depicted a harsh stereotype of urban immigrants.

Most people probably don't think of the Caribbean when they think of cannibalism (rather, a bloody Anthony Hopkins comes to mind…). But the term derives from the tribe Canibales, or the Caribs, in the West Indies. Allegedly, this ancient tribe was known for eating each other.

The phrase "mumbo jumbo" likely comes from the West African god Maamajomboo. Why is it offensive? Apparently, Mandinka males would dress up like the god to solve domestic disputes and abuse their wives.

Fuzzy Wuzzy was a bear… but before that, he wasn't so innocent. In the 1800s, British colonial soldiers referred to the people of an East African nomadic tribe as "fuzzy wuzzies" due to their dark skin and curly hair. The term was later picked up by other military groups to refer to other indigenous populations in places like Papa New Guinea and Sudan. And for more outdated phrases, check out the 20 Slang Terms From the 1990s No One Uses Anymore.

There's a reason that the phrase "no can do" sounds like broken English. The saying cropped up in the mid-1800s—a time when Westerners widely held a racist attitude toward the East—as a way to mock simplified Chinese Pidgin English.

This saying for a person who has difficulty coping was first used during World War I to describe a person who had lost all four limbs and had to be carried in a basket.ae0fcc31ae342fd3a1346ebb1f342fcb

The term "moron" wasn't originally an insult, but a psychological diagnosis denoting a mild disability.

No one knows for sure where this phrase comes from, but experts believe it has something to do with an English law from the 1600s that allowed men to assault their wives with a stick—just so long as it was no wider than his thumb in thickness. Again… Yikes!

Today, the second line of this children's rhyme is "catch a tiger by the toe," but the original version included a ghastly racial slur.

Contrary to popular belief, "Eskimo" isn't the proper term to describe people indigenous to northern Canada and Alaska. The word is actually an offensive way to refer to the Inuit people; it derives from the Danish loanword ashkimeq, meaning "eaters of raw meat."

In the 1970s, members of the Peoples Temple led by Jim Jones committed mass suicide by drinking a soft-drink laced with cyanide and various prescription drugs. Thus, today people use the phrase "to drink the Kool-Aid" to refer to someone with unwavering and unconditional loyalty.

Records show that the phrase "long time no see" was first uttered by a Native American. In print, William F. Drannan used the phrase in one of his novels to describe an encounter with a Native American: "I knew he had recognized me. When we rode up to him he said: 'Good morning. Long time no see you,' and at the same time presented the gun with breech foremost." Like "no can do," "long time no see" mocks the Native Americans' broken English.

Unfortunately, this phrase doesn't stem from some strange story about a man whose tongue was literally pawed by a cat. Rather, The English Navy used to use a whip called the "Cat-o'-nine-tails" to flog victims, and the pain was so intense that those on the receiving end of the blows couldn't speak. Hence, the meaning of the phrase today.

Back in the days when almost all medical problems were treated with lobotomies and illicit drugs, doctors used "hysteria" as a medical explanation for nearly every sick woman they encountered. The idea for such a diagnosis comes from Hippocrates' belief that a woman's hysteria is caused by a "wandering uterus" that is deprived of sexual pleasure.

When you reach the tipping point in a situation, you have reached the point at which "a change or an effect cannot be stopped." This seems benign enough, but the phrase was used in the '50s and '60s to reference the tendency for white families to move out of a neighborhood once it had been taken over by an African American majority.

Historically, white people would describe black men as "boys" to indicate that they were not on equal playing fields. The U.S. Supreme Court even declared that the word is "not benign" and considers its use in certain contexts to be racist.

Today, when a person goes "off the reservation," they've lost control. But its origins are even more sinister. As Native Americans were once restricted to reservations created for them by the government, people would historically use this phrase to refer to Native Americans who had strayed from their land, often with contempt for the indigenous people.

Once upon a time, the word "spinster" didn't refer to an unmarried woman, but a person who spun yard or thread for a living. Eventually the term took on its current meaning, as most of the women who were spinsters were also lower-class and unwed, relying on their job to provide for themselves.