From Old English 'clēowen' (ball of thread). The modern meaning comes from Greek myth: Ariadne gave Theseus a ball of thread to navigate the Minotaur's labyrinth. By the 1590s, a 'clew' meant anything that guides you through complexity. A clue is literally a thread you follow.
A piece of evidence or information used in the detection of a crime or solving of a mystery.
Variant spelling of 'clew', from Old English 'clēowen' / 'cliewen' (ball of thread or yarn), from Proto-Germanic *kliwją (ball, clew). The modern meaning 'piece of evidence' derives from the myth of Theseus and the Minotaur: Ariadne gave Theseus a ball of thread ('clew') to unwind as he entered the labyrinth, so he could follow it back out after slaying the Minotaur. By the 1590s, 'clew' metaphorically meant anything that guides one through
A 'clue' is literally a ball of thread. The entire modern meaning — detective work, mystery solving, crime investigation — comes from a single Greek myth: Ariadne's thread in the labyrinth. When we say someone 'hasn't got a clue', we're saying they have no thread to follow out of the maze. The nautical term 'clew' (the lower corner