Clue: Ariadne's Thread
Every detective story, every mystery novel, every crime procedural uses the word *clue* — and none of them are aware that they are talking about a ball of yarn. The word *clue* is a spelling variant of *clew*, which meant, in Old English, a ball of thread. Its modern meaning — a piece of evidence that helps solve a mystery — comes entirely from a single Greek myth: the story of Theseus, the Minotaur, and Ariadne's thread.
The Old English Word
Old English *clēowen* (also *cliewen*) meant a ball of thread or yarn — the kind produced by winding spun fiber into a sphere. The word descended from Proto-Germanic *\*kliwją* (ball, lump), with cognates in Dutch *kluwen* and German *Knäuel* (ball of yarn, tangle). For centuries, this was the word's only meaning: a physical object, a domestic tool used in spinning and weaving.
The nautical term *clew* — the lower corner of a square sail, where the ropes gather — is the same word. The corner of the sail is where the fabric's threads converge into a point, like thread winding into a ball.
The Myth
The transformation from 'ball of thread' to 'piece of evidence' is owed to one of the most famous stories in Greek mythology.
King Minos of Crete kept the Minotaur — a monster with the body of a man and the head of a bull — imprisoned in a labyrinth designed by the architect Daedalus. Every nine years, Athens was forced to send seven young men and seven young women into the labyrinth as sacrifices. The hero Theseus volunteered to enter the labyrinth and kill the Minotaur.
Ariadne, Minos's daughter, fell in love with Theseus and gave him a ball of thread (*a clew*) to unwind as he entered the labyrinth. After slaying the Minotaur, Theseus followed the thread back through the maze to safety.
The ball of thread was the thing that solved the unsolvable problem — the guide through the maze, the means of finding one's way when all directions looked the same.
The Metaphorical Leap
By the late sixteenth century, English writers had begun using *clew* figuratively. If you had 'a clew' to a problem, you had something to follow — a thread of reasoning, a guide through intellectual complexity. The earliest figurative uses still explicitly referenced the Theseus myth; later uses dropped the mythological reference and kept the meaning.
The spelling *clue* appeared in the seventeenth century as a variant and gradually displaced *clew* for the figurative sense, while *clew* survived in nautical usage. By the nineteenth century, *clue* was firmly established as a word of detection and investigation, and its origin in balls of thread was largely forgotten.
The Detective Tradition
The word *clue* became central to detective fiction from its earliest days. Arthur Conan Doyle's Sherlock Holmes follows clues; Agatha Christie's plots are built on clues; the board game *Cluedo* (marketed as *Clue* in North America) takes the word as its title. In each case, the metaphor is consistent: a clue is a thread that, if followed, leads out of the labyrinth of mystery.
The phrase 'hasn't got a clue' — meaning someone is utterly lost — is the perfect etymological descendant. To have no clue is to have no thread, to be trapped in the labyrinth with no way out.
Unraveling
The related word *unravel* extends the textile metaphor: to *unravel* a mystery is to pull apart the tangled threads until the pattern becomes clear. *Thread* itself is used metaphorically — 'a thread of evidence', 'the thread of an argument', 'losing the thread'. English is saturated with textile metaphors for thinking and reasoning: *text* comes from Latin *textus* (woven), *fabric* from *fabricāre* (to construct), and *clue* from a ball of yarn.
A Word Spun From Myth
*Clue* is one of the clearest examples of myth shaping everyday language. A Greek princess gave a hero a ball of thread; two thousand years later, English speakers used the word for that ball of thread to mean 'evidence'. The myth is forgotten; the metaphor survives. Every detective who follows a clue is, unknowingly, following Ariadne's thread through the labyrinth — unwinding the ball, one step at a time, toward the monster at the center.