A ball or skein of thread or yarn.
Something that guides through an intricate problem.
Information that points toward an answer.
A detective’s clue began as a ball of thread — and a way through a maze.
First, a ball of yarn
The older English word clew meant a ball of thread or yarn. It descends from Old English cliewen, a word for a ball or skein. This was an ordinary physical object long before it became an abstract hint.
Ariadne and the labyrinth
In the Greek myth, Ariadne gives Theseus a thread to help him find his way out of the labyrinth after confronting the Minotaur. The image of a thread leading someone through confusion helped give clew a figurative meaning: something that guides a search.
How the spelling changed
The spelling clue appeared in the fifteenth century. By the late sixteenth century, the word could mean a guide in a complicated situation; the more general sense of a hint or piece of evidence developed from that guiding idea.
The mystery-writing connection
When a detective follows clues, the metaphor is remarkably close to its older form: each useful detail is a thread that might lead out of a maze of possibilities. The myth helps explain the metaphor, but the word for a ball of yarn is older than the myth-based figurative use.
Was the word clue invented by Greek mythology?
No. The English word already existed as a name for a ball of thread. The labyrinth story helped shape its later meaning of guidance or evidence.
Check the evidence
Dates are approximate and reflect recorded evidence, not the moment a word was first spoken. Read our research approach.
Editorial review: October 2026. Report a correction.