The Fascinating Origins Behind 8 Peculiarly Named Body Parts

Ever wondered why the back of your lower leg shares its name with a young cow? Or why the sole of your foot is named after a fish? Dive into the surprising linguistic roots of these curiously named body parts.

Calf

This is purely coincidental. The term calf for a baby cow and the calf at the back of the lower leg are homographs—words with distinct origins that evolved to share the same spelling and pronunciation. The word for the young cow derives from Old English cælf, rooted in Germanic language. Meanwhile, the anatomical term originated in the Middle Ages, tracing back to Old Norse kálfi.

Sole

On the flip side (or perhaps the other foot?), the fish and the anatomical sole share a connection. The term sole, referring to the underside of a foot, made its way into Middle English through Old French, originating from the Latin solea, meaning "sandal" or "sill." This, in turn, stems from solum, which translates to "bottom," "pavement," or—surprisingly—"sole." The fish earned its name due to its resemblance to the shape of a foot's sole.

Palm

What links the inner part of your hand to the trees found on Hawaiian beaches? Palm trees aren’t exclusive to tropical islands. In ancient Rome, victors in competitions were traditionally given a palm leaf to hold. The Latin word palma (or palmus), meaning "palm of the hand," eventually became tied to the tree. Interestingly, the Romans also used palma to describe the underside of a webbed foot.

Elbow

If you assumed the –bow in elbow relates to bending (even if it doesn’t curve as gracefully as a rainbow or a crossbow), you’re correct. But what’s the story behind el-? The Old English ęln, meaning "arm or forearm," is connected to the Latin ulna, which also referred to the forearm and is now the name of the inner bone in the forearm. Additionally, el- is linked to ell, a unit of length often measured from the elbow to the wrist, likely causing disputes between long-armed buyers and short-armed fabric sellers.

Thumb

The term for the short, sturdy, opposable finger on the human hand traces back to Old English thūma, originating from the Indo-European root teuə-, meaning "to swell." Related words include thigh, thousand, thimble, tumor, butter, tomb, and tumescence. Remember this the next time you give someone a thumbs-up.

Index finger

This digit earned its name not from its role in navigating books but because it’s primarily used for pointing or indicating. The term index originally meant "the forefinger" in the late 1300s. It wasn’t until a few centuries later that it came to signify "an alphabetical list directing readers to specific names or topics in a book."

Pupil

What connects the opening in the eye that lets light enter the retina to a young learner? The term pupil, initially meaning "orphan" or "ward," entered late Middle English from Old French pupille, derived from Latin pupillus (a diminutive of pupus, meaning "boy") and pupilla (a diminutive of pupa, meaning "girl"). By the 16th century, it evolved to mean "a person being taught by another." The pupil of the eye also comes from Old French pupille, originating from Latin pupilla, but with the added meaning of "doll" rather than "little girl." Why a doll? Lexicographers suggest it’s due to the tiny reflection visible when you look into someone’s pupil.

Iris

Speaking of the eye, why does its colored part share its name with a flower? Both the eye’s colorful ring-shaped membrane and the flower are named after Iris, the Greek mythology goddess of the rainbow.

References: OED [Oxford English Dictionary] Online, New Oxford American Dictionary (Second Edition), The American Heritage Dictionary of the English Language (Fifth Edition)