Where does the word clue come from?
What most people think: Most people assume clue was always a detective word meaning a piece of evidence.
Guess before the Apple does
Just tell me the answer
Clue comes from 'clew', an old word for a ball of thread. It took on its modern meaning from the Greek myth of Theseus, who used a ball of thread to find his way out of the Labyrinth.
Every crime novel, every crossword and every frustrated parent asking a teenager whether they have a clue owes something to a ball of string. Not a magnifying glass, not a fingerprint. String. And a half-bull monster from ancient Crete.
The short answer
Clue began as clew, meaning a ball of thread or yarn. It comes from Old English, with relatives such as Dutch kluwen and German Knäuel. The idea of a clue as something that guides you through a puzzle comes from the thread that leads you out of a maze.
The real story
In Greek myth, the hero Theseus enters the Labyrinth on Crete to kill the Minotaur. Ariadne gives him a ball of thread. He unwinds it on the way in, slays the monster, then follows the thread back out. The thread is literally the thing that gets him from confusion to a solution.
English writers told this story using the native word for a ball of thread. Geoffrey Chaucer, retelling it in The Legend of Ariadne around 1385, speaks of a clewe of twyn, a ball of twine. From there it was a short hop to using the word for anything that guides you through a tangled situation. That sense, a clue as a guide in an intricate case, is recorded in the 1590s, and the fully figurative sense of something that points the way follows in the 1620s.
A lovely example: in 1699 the poet John Pomfret wrote of someone who “treads the Maze of Life without a Clue”. He still meant a guiding thread, but you can feel the modern meaning arriving.
The spelling changed too. Middle English liked endings in -ew, but many later shifted to -ue, which is why we write blue and glue. Clue followed the same path. The spelling is first seen in the mid-1400s, though it stayed less common than clew until the 1600s.
Why people get it wrong
Clue now lives so completely in the world of detectives, puzzles and the board game Cluedo, launched in Britain in 1949, that it is hard to imagine it ever meant anything else. Nobody thinks of knitting when they hear Sherlock Holmes say it.
The thread meaning also faded from everyday speech. The spelling clew lingers mostly in sailing, where clew lines are used to haul up sails, and in regional dialects. With its origins out of sight, people assume the detective meaning is the original.
Even clueless has a twist. When it appears in 1817, it means trackless, with no trail to follow. The insult meaning ignorant does not turn up until 1943.
“Next time someone says you haven’t got a clue, tell them you’re fine for string, thanks.”
Sources
Fact-checked 31 Oct 2026. Spotted a mistake? Tell us and we'll fix it in public.
