#Origins of the naughtiest swear words in the English language

In most people, language is generated on the left side of the brain — the half associated with logic, motor functions and math. 

But when we let loose with a particularly satisfying swear word, the right side of our gray matter — associated with emotion and cathartic expression — lights up on imaging scans, reveals Columbia linguistics professor John McWhorter. 

“Curse words are not words, in a sense,” McWhorter told The Post. “They’re eruptions.” 

McWhorter loves swear words so much he’s written a book about their origins, “Nine Nasty Words: English in the Gutter: Then, Now, and Forever” (Avery), out May 4. 

“I think we all enjoy transgression. We enjoy being bad,” he explains. “There’s an inner toddler in all of us.” 

To research his biography on blasphemy, McWhorter started with comedian George Carlin’s infamous “seven dirty words,” and revised the list to include “all the words anyone would think of,” he says. 

He found that, over the centuries, what we find offensive has changed. Back in medieval times, for example, when people as a whole were much more religious, the idea that you would swear to God was “a big deal.” 

“Damning, and the place one was usually damned to, was taken literally,” the author writes. 

But over the years, what started as, “God damn that man” was shortened to “damn” and became less a “command to condemn,” as much as a “mere bark of annoyance,” McWhorter writes. 

Now it’s lost so much of its power we can print it in full. 

As the power of religion faded, the body soon became the source of profanity, especially in matters related to sex and excrement — both functions that were once more public before moving behind closed doors with the rise of personal privacy. 

Take the F-word, which emerged “quietly out of the mists of time,” the author writes. 

One theory is that the word is derived from the German ficken, which once meant to rub. McWhorter says that’s unlikely, because Old and Middle English speakers weren’t known to borrow words from German. 

Another possibility is that it comes from the Vikings, who invaded England in 787. 

“A now obsolete Norwegian word like fukka would have been a fine candidate for what became our four-letter word of choice,” the author writes. “No squinting is necessary — fukka meant exactly what it looks like.” 

One other possibility, the author says, is that the F-word has its roots in Old English and that no clear trail survives. “One of the hardest things about tracing curse words is people aren’t going to write them down,” McWhorter says. 

“After the 1500s, ‘f–k’ is rarely printed,” the author writes. The word does not appear in the dictionary from 1795 to 1965, “yet there are endless indications that the word was thriving and even exploding in real life despite its near-absence in print.” 

The earliest unequivocal use comes in 1528 when an anonymous monk wrote a parenthetical into the annotations of Cicero’s “De Officiis” calling out a “f–kin’ abbott.” 

McWhorter says the monk was probably using it in the “dismissive sense,” like we might exclaim “f–kin’ taxes,” and its inclusion “lets us know that the basic sexual word f–k had long existed before.” 

The S-word has a similarly obscure origin story. 

One legend holds that it’s an acronym for “ship high in transit.” 

But McWhorter says that’s bunk. The term has been in use for more than a 1,000 years, before a word such as “transit” even entered the language. 

Its origins instead lie in a language once spoken in what is now Ukraine. Those people had a word skei, meaning “cut off” or “slice.” Some of their descendants settled in England, and over the millennia, skei morphed into scit. 

“But in Old English, its meaning had drifted into a particular kind of cutting off,” the author writes. “Likely some people along the way started referring to defecation as going to ‘cut one off.’ ” 

That “sc” soon turned into a “sh,” and the rest is wash-your-mouth-out-with-soap history. 

Slang names for certain body parts have also evolved in fun ways. 

“Dick” started as a generic term for “fella,” as in every Tom, Dick and Harry. Its meaning eventually took on another meaning because of “a certain anthropomorphization of the penis,” the author writes. 

The first in-print usage probably appeared in a 1654 play which contained the putdown, “thou feeble dick.” 

Meanwhile, McWhorter argues that a tendency towards “cuddlier” nicknames for female genitalia may have led to the P-word. 

Once used as a term of endearment for women, it also developed a dirty double meaning. 

The first printed usage comes in a 1699 poem about a man who is unable to satisfy his much younger wife, and so he hires a young stud to “feed” her you-know-what. 

The term probably goes back hundreds of years, and may have been brought to us by the initial invaders of England, the author writes. 

VIDEO WARNING: EXPLICIT LANGUAGE

Low German had the word puse used for both a cat and as an anatomical reference. 

“The evidence suggests, then, that not just Abraham Lincoln but likely George Washington and possibly even Oliver Cromwell were familiar with p—y as a sexual term,” he writes. 

Then there’s Samuel L. Jackson’s favorite word, which we’ll abbreviate as “mf.” 

Unlike other curse words, it does not appear to have a long history stretching back to medieval times and seems to have appeared late in the swearing game. 

In 1831, the conjoined twins Chang and Eng were assaulted by a man who used “opprobrious epithets in relation to their mother,” as was reported at the time, though it’s unclear exactly what was said. 

“Mf” began explicitly appearing in the late 19 century, “first intended in its literal meaning, but gradually becoming a near-nonsense eruption,” the author writes. 

The earliest usage known came in 1890, when the Texas Court of Appeals reported someone saying, “that God damned motherf–king, bastardly son-of-a-bitch!” 

McWhorter, who has two kids aged 6 and 9, says he uses profanity around the house and expects his children will, as well. Some swear words are just words and don’t cause any harm, he says. 

The message of his book, he says, is that we need to rethink our ideas about profanity altogether. 

The real forbidden words, he says, should be slurs, such as the N-word or “f—-t,” which originally meant a bundle of sticks but morphed to mean a placeholder soldier, then a worthless person, a worthless woman and finally in the late 1800s, a homosexual man. 

But “the idea of s–t and f–k are profane? I find that Mormon and old-fashioned,” he says. “We need to stop getting our knickers in a twist when some celebrity says s- -t.”