n. 25B6; noun
police are searching for clues : HINT, indication, sign, signal, pointer, trace, indicator; lead, tip, tip-off; evidence, information.
a crossword clue : QUESTION, problem, puzzle, riddle, poser, conundrum.
25A0; clue someone in/up (informal) INFORM, notify, make aware, prime; keep up to date, keep posted; informal tip off, give the gen, give the low-down, fill in on, gen up on, put in the picture, put wise, keep up to speed.
25A0; not have a clue (informal) HAVE NO IDEA, be ignorant, not have an inkling; be baffled, be mystified, be at a loss; informal be clueless, not have the faintest.