What does clew mean?
A clew is the lower corner of a sail — specifically the corner farthest aft on fore-and-aft sails such as jibs and mainsails, or either of the two lower corners on square sails. It is the point at which the sheet, the rope used to control the sail's angle, is attached, making the clew central to the business of trimming sails and harnessing wind efficiently. The word carries an older, now largely obsolete sense: a ball of thread or yarn, the very object that guided Theseus out of the labyrinth in Greek myth. From that image of a guiding thread came the figurative word 'clue', which began life simply as an alternative spelling of 'clew'. Today 'clew' survives almost entirely at sea, prized by sailors and riggers for its precision, while its twin 'clue' went ashore and conquered everyday language. Knowing both words offers a neat glimpse of how a single term can split into two lives — one technical, one metaphorical.
The lower or aftermost corner of a sail, to which the sheet is attached.
"He trimmed the sheet until the clew of the genoa curved just right."
Primarily used by sailors and in technical sailing literature.
Archaic: a ball of thread or yarn.
"She wound the wool into a tidy clew before beginning to knit."
Regular plural formation; used when referring to multiple sail corners or balls of thread.
"Both clews of the square sail were secured before the squall hit."
Theseus's legendary ball of thread was a 'clew' — and that ball of string is literally where our modern word 'clue' comes from.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of clew
Clew descends from Old English 'clīwen' or 'clēowen', meaning a ball of thread or yarn, and is cognate with similar forms in other Germanic languages such as Middle Low German. The nautical sense developed because the corner of a sail gathered into a compact point resembled a wound ball of yarn. The spelling 'clue' emerged as a variant and eventually monopolized the figurative sense of something that guides one through a maze or mystery, leaving 'clew' to retain the literal senses.
Related word forms
How clew is actually used
In modern English, 'clew' is almost exclusively nautical and technical, while its historical rival spelling 'clue' has taken over all figurative senses. The plural is regular ('clews'). Sailors distinguish the clew from the tack (the other lower corner) and the head (the top of the sail), so precision matters in rigging contexts.
Easily confused with clew
Clue means a piece of evidence or hint that helps solve a problem, while clew is chiefly the corner of a sail — though 'clue' actually arose as a spelling variant of 'clew'.