(informal) To inform or tell.

(now rare) A strand of yarn etc. as used to guide one through a labyrinth; something which points the way, a guide. / Information which may lead one to a certain point or conclusion.

To provide with a clue. / To provide someone with information which he or she lacks (often used with "in" or "up").

present participle of clue

The board game Cluedo whose goal is to solve the mystery of a fictitious murder.

Response affirming that the speaker does not have knowledge pertaining to an interlocutor's question

plural of clue

Third-person singular simple present indicative form of clue

present participle of have a clue

(idiomatic) A metaphorical stick used to beat information or understanding into a slow learner.