Ask an anatomist, and they’ll be able to tell you that your kneecap is really your patella. Your armpit is your axilla, and the little groove above your top lip is your philtrum. The little flap of cartilage the covers the hole in your ear? That’s your tragus, named after the Greek word for a billy goat—because the tuft of hair that grows on it resembles a goat’s beard (apparently).
But if that’s what’s on the outside, what about what happens on the inside? The English language has a rich collection of formal, medical, and old fashioned words for all of the reflexes and reactions that our bodies naturally carry out without a second thought from us. So the next time you’re stretching as you get out of bed, or you interrupt an important meeting with a ructus or a borborygmus, you’ll at least have the perfect word for it.
Derived originally from an onomatopoeic Greek word, borborygmus is a rumbling in the stomach or bowels. Borborygmi are produced as the contents of the intestines are pushed along by waves of muscle contractions called peristalsis, although trapped gas from digested food or swallowed air can also cause your borborygmi to become noisier than normal. Bonus fact: Queasy stomach rumbles were called wambles in Tudor English, and you’d be wamble-cropped if you weren’t feeling well.
A study in 2013 found that when people laugh, it’s only because they’ve found something funny about 20 percent of the time. The rest of the time, we use laughter as a means of signaling things like agreement, affection, ease, and nostalgia that we evolved long before communication through language was possible. And a fit of spontaneous, uproarious, unrestrained laughter is called cachinnation.
Cicatrization is the formation of a cicatrix, or a scar. More generally, it refers to any of the healing and sealing processes that help a wound to mend, including the formation of a scab.
Deglutition is the proper word for the action of swallowing. It’s an etymological cousin of words like glut, glutton, and gullet.
Sweating has been known by a whole host of (ironically quite beautiful) words in history, including the likes of resudation, sudorification, and diaphoresis, a 17th-century word that literally means “to carry through.” Nowadays, diaphoresis is rarely encountered outside of purely medical contexts, where it’s used as an older or more formal name for excessive perspiration—a condition better known as hyperhidrosis.
As well as being another word for a volcanic eruption, eructation is the medical name for burping, while the burp itself is called a ructus. The Romans called excessive or unstoppable belching as ructabundus (although sadly that word has yet to catch on in English).
So if a ructus is a burp, no prizes for guessing that a flatus goes the other way. Technically though, flatus is just the build-up of gas in the stomach or bowels, not the actual expulsion of it. For that, why not try using an old Tudor English word for a fart—ventosity.
Horripilation literally means “bristled hairs,” and is the proper name for what you probably know as gooseflesh or goosebumps. Another name for the same thing is piloerection, although that also includes the phenomenon of animals raising their hair or fur (or, in the case of porcupines, their quills) when they’re stressed or under attack.
Lachrymation is the proper name for shedding tears, which are produced in the lachrymal glands above the outer edges of the eyes and are stored in a lachrymal sac on either side of the bridge of the nose. And if you want to get really technical, there are three different types of tears: basal tears, which are constantly produced to keep the surface of the eyes moist; reflex tears, which are the extra tears produced when something enters or irritates the eye; and psychic tears, which are those produced as a response to a mental or emotional stimulus.
Mastication is the proper name for chewing. Etymologically, it’s descended from a Greek word literally meaning “to gnash your teeth,” and is related both to mandible and papier-mâché (which is literally “chewed paper” in French).
Nictitation is the proper name for blinking or winking, and comes from an old pre-Latin word meaning “to incline or bend together,” just as the eyelids do. That twitching muscle in your eyelid after you’ve strained your eyes? That’s a blepharospasm.
Obdormition is the proper name for sleeping, but it’s usually only used in reference to the feeling of numbness, caused by pressure on a nerve, when a limb or muscle “falls asleep.” Pins and needles, incidentally, is properly called paresthesia.
Pandiculation is essentially a catchall term for all those things you do when you’re tired or just waking up, like yawning, stretching your arms and legs, and cracking your joints. Monday morning, in other words.
In Latin, singultus was speech interrupted by sobbing, or an inability to speak caused by crying. Based on this, English borrowed the word singult in the 16th century for a single sob, in the sense of something spasmodically interrupting your speech, and singultus came to be used as a more formal name for hiccups.
Tussis is the Latin word for “cough.” It’s the origin of both tussication, a formal word for coughing, and pertussis, the medical name for whooping cough.
A version of this story ran in 2017; it has been updated for 2023.