Definition of clues:
(n) :
Information which may lead one to a certain point or conclusion.
(n) :
Insight or understanding ("to have a clue [about]" or "to have clue". See have a clue, clue stick)
(n) :
An object or a kind of indication which may be used as evidence.
(v) :
To provide someone with information which they lack (often used with "in" or "up").
(v) :
To provide with a clue.
(n) :
(now rare) A strand of yarn etc. as used to guide one through a labyrinth; something which points the way, a guide.