—n.
1 a fact or idea that serves as a guide, or suggests a line of inquiry, in a problem or investigation.
2 a piece of evidence etc. in the detection of a crime.
3 a verbal formula serving as a hint as to what is to be inserted in a crossword.
4 a the thread of a story. b a train of thought.
—v.tr. (clues, clued, cluing or clueing) provide a clue to.
Phrases and idioms:
clue in (or up) sl. inform. not have a clue colloq. be ignorant or incompetent.
Etymology: var. of CLEW
Useful english dictionary. 2012.