■ noun a fact or piece of evidence used to solve a crime or that serves to reveal something.
■ verb ( ~s , ~ing , ~d ) ( ~ someone in ) informal inform someone about something.
Phrases
have a ~ [usu. with negative ] informal know about something or about how to do something.
Origin
ME (orig. 'a ball of thread', hence one used to guide a person out of a labyrinth): var. of clew .