On Halloween, one word reigns supreme: Boo.
Usually lodged at an unsuspecting target, the short ― and, coincidentally, pretty sweet-sounding ― utterance is meant to scare. “Boo!” your friend Karen might shriek after sneaking up on you at a bar.
But more than that, “boo” is supposed to be the sound a ghost makes. Anyone who’s worn a sloppily draped bedsheet and attempted to imitate the dearly departed come back to haunt us has done one of two things: flailed their arms wildly and/or sputtered an elongated, “Boooooo.”
So where does the word “boo” come from?
According to Merriam-Webster Dictionary, “boo” comes from the Middle English “bo,” which was used in writing as early as the 1500s. It “was used as an interjection that was meant to either surprise or frighten,” Merriam-Webster’s Kory Stamper explained to The Huffington Post. An early example of “bo” in print can be seen in a tale about a smith who made a woman for himself:
What, evyll hayle! sayd he / Wylt not thou yonge be? / Speke now, let me se, / And say ones bo!” (Lo, evil health, said he / Will you not young be? / Speak now, let me see / and say “bo”!)
― “The tale of the smyth and his dame,” 1565
“Sort of fitting for Halloween,” Stamper noted.
Several writers and experts, including Slate editor Forrest Wickman, claim an early use of “boo” in print dates back to the 18th century, in Gilbert Crokatt’s 1738 tome Scotch Presbyterian Eloquence Display’d. Stamper sent us the following quote from the book:
Boo is a word used in the North of Scotland to frighten crying children.
At some point along the way, “boo” ― or, more accurately, “bo” and boh” ― became attached to ghosts. Stamper references historical records from the early 1800s showing that ghosts (or, let’s be real, people pretending to be ghosts) used variations of the word. Even further back than that, a 1672 poem by Robert Wild reads, “The Pope’s Raw-head-and-bloody-bones cry Boh Behind the door!” evidence of the fact that “boo”’s etymological cousins were attributed to boogeymen and other monsters throughout the 16th and 17th centuries.
“So while the world wasn’t spectral right away, it certainly was still spooky,” Stamper added.
Is there something innately scary sounding about the word “boo,” though? “We derived the word by phonetically spelling the common sound that people made when they wanted to surprise or frighten someone,” Stamper said. That common monosyllabic sound, the Oxford English Dictionary says, results from a “combination of a consonant and a vowel especially fitted to produce a loud and startling sound.”
“The combination of the voiced, plosive b- and the roaring -oo sounds makes boo a particularly startling word,” Wickman writes over at Slate. “Some linguists argue that the ‘ooh’ or ‘oh’ sounds can be pronounced at a higher volume than other vowel sounds, such as the ‘ee’ in ‘wheel.’” This makes particular sense when considering the prevalence of “boo”-related scare sounds in other languages.
“Boo” has other uses; most commonly, as a verb or noun that expresses disapproval. Think: “He booed the home team,” or “he showered the team with ‘boos.’” But Stamper guesses that the “frighten” sense of the interjection predates the heckling one, which probably originated in the 1800s. (One of our favorite “boo” theories is that ghosts only haunt people they don’t like, thus they boo people from the afterlife.)
Then there’s the romantic “boo” ― think: “Greg and I have been on three dates, I guess he’s my new boo.” ― dating back to the 1980s as, OED surmises, an alteration of the French “beau.”
But nothing beats the O.G. “boo,” forevermore the sound a costumed wraith makes on Halloween. In honor of the holiday, we’ll leave you with a little Latin joke that sums up the beauty of “boo”: