In 1979, Johnny Carson told millions of television viewers he wanted to have sex. But only about a hundred people knew what he was talking about.

“If I was going to ‘burlap’ somebody, would that be good or bad?” he asked his guest, Bobby Glover, a resident of Boonville, California.

“I’d say it would be good,” Glover replied.

“Those people up in Boonville know what I’m talking about, huh?”

“They are rolling on the floor right now,” said Glover. The audience, who finally understood the joke, roared.

You see, Boonville residents had invented their own secret language, called Boontling, around the turn of the 20th century. By the time Carson heard about it, the language contained some 1,600 words built around English syntax. For instance:

Boontling: “The crazeek eeld’m hooted and charlied at the bollnesses branching at the hob.”

Translation: “The crazy old woman laughed and embarrassed all the pretty young women having a good time at the Saturday night dance.”

But before its bounteous vocabulary, Boontling started as a way to talk about sex.

Boonville is a tiny town that plugs the southern tip of the Anderson Valley, a fertile region known for its wine, apples, and cattle just off the Northern California coast. The hamlet’s first residents, about 19 families in all, settled around 1865. For decades, they lived in relative isolation; few visitors traversed the winding roads into Boonville. According to a 1966 essay, “‘Boontling’: Esoteric Speech of Boonville, California,” one man bragged that in his 70 years, he had never left the valley.

The area’s remoteness partially explains how the Boontling language came to be, and why it remained local. But how the dialect grew — to the point it was taught at the local elementary school — is owed entirely to the peculiarities of the town itself.

Though its origins are debated, old timers attribute the language to a group of gossiping women. Around 1890, a young pregnant woman moved to town from Ukiah, about 20 miles northeast. Her family had banished her. She began working in the hop fields alongside the Boonville women. Eager to discuss the scandal, the ladies developed a series of coded words and phrases to evade her attention. Classic mean girls.

Soon, their husbands took to the language and started using it at the sheep-shearing pens where they worked. Children began speaking it to undermine their parents. Schoolteachers had to learn it to keep order in the classroom.

The Boontling language, comprised mostly of nouns, verbs, and adjectives, was crafted around hyperlocal references that only those embedded in the tight-knit community would understand. For instance, a doctor was a shoveltooth because the first resident physician had protruding teeth; a wealthy man was known as a high pockety because Boonville’s richest resident was very tall (i.e. high pockets). One was blue-birded if he got bucked off a horse, a phrase traced to a young boy who, after he was bucked, said, “I got thrown so high that a bluebird could have built a nest on my ass.” An infusion of Appalachian-style humor, Scotch-Irish tradition, Spanish, and local Pomo Indian dialect informed the expanding vocabulary. Boonters called apples gannows, after gano, a Spanish word for a type of apple grown nearby; a keishbook was a Pomo word for pregnant woman. Since the language was mostly spoken, spelling was inconsistent and mostly phonetic. It would make sense, then, that onomatopoeias were common in Boontling — “to ride a train” is to kelockity, and charl is the word for milk as it’s pulled from an udder and echoes inside a tin pail.

Soon, Boontling overtook entire conversations, rather than punctuated slang here and there, à la Clockwork Orange. Some residents would later boast of the language’s ability to abbreviate sentences. Grannyhatchet, shied shaggy meant, briefly, “It was a buck with large antlers [above]; he appeared to be crippled as he ran away.” One might complain to the doctor of feeling tongue-cuppy, the motion one’s mouth makes before vomiting. Local resident Charlie (Shot) Wallach told Smithsonian magazine in 1984, “If we keep workin’ on this Boonville lingo, we can say ‘tweety-tweet-tweet’ and get three days’ talkin’ done.”

The language proved useful in other ways. Boonville soldiers fighting in World War I wrote entire letters home in their local jargon, containing locations and other sensitive intel the military would normally have censored. The local kids’ baseball team signaled secret plays and befuddled opposing teams.

And later, Johnny Carson used it to talk about sex. The story goes: Around the turn of the 20th century, two men on horseback rode up to the general store for supplies. Finding no one behind the counter, one man looked in the back room for help. There he found the store owner and his girlfriend having sex on a pile of burlap sacks. “Why,” he blurted to his friend, “they’re burlappin’ in there!” It stuck.

In 1960, a lexicography professor from the California State University, Chico, Charles C. Adams, began to study Boontling, which he called a “fascinating linguistic phenomenon,” though not technically a language. Nevertheless, he spent time with the famously guarded and skeptical residents of Boonville, who called him a gray-matter kimmie (professor) and a bright-lighter (city slicker).

“They take you in by degrees,” Adams would later write. “Boonters are protective of the language because it is intensely personal. Many of the words were derived from and intertwined with the names of their friends and neighbors, and they weren’t always flattering.” The Boontling terms for “drunk” and “tattletale” derive from the names of local residents. As much as 15 percent of the lexicon was made up of words for taboo topics, like burlap.

Eventually, Boonville grew to trust Adams, who compiled a complete dictionary and history of Boontling. In return, Boonters gave Adams his own nickname, B.J., after an earlier resident also called Adams.

By that time, Boontling’s heyday was over. At its height between 1890 and the 1920s, the entire town’s 1,000 or so residents could speak and understand the dialect. But with the increase in transportation technology and new roads to the area, locals moved away and newcomers took their place. Boontling was pikin’ to the dusties, being swept away.

Some traces of it remain today. According to elderly residents, alternating generations resurrect old Boontling phrases from time to time. The Anderson Valley Brewing Company uses it to lend local charm to beer marketing (bahl hornin’ translates to “cheers”). And up until 2010, Boonville operated the Horn of Zeese (translation: A Drink of Coffee), a diner and Boonter hangout where one could order coarp slibs and easters (ham and eggs) or jeffered boos (french fries).

By 2013, the latest numbers available, only 12 or so Boontling speakers remained. And they still blush over burlappin’.