- clue (n.)
- 1590s, phonetic variant of clew "a ball of thread or yarn," with reference to the one Theseus used as a guide out of the Labyrinth. The purely figurative sense of "that which points the way" is from 1620s.
- clue (v.)
- "to inform someone of the important facts," usually with in, 1934, from clue (n.). Related: Clued; cluing. Earlier in 19c. sailing, "to man clue lines so as to force a yard down on the mast cap."