Wiktionary
have a clue
vb. To be knowledgeable about a topic or situation.
Usage examples of "have a clue".
I burst out laughing because all the costermongers in the Whitechapel Road always did whenever they heard that word, although I admit that at the time I didn't have a clue what a virgin was.
But it is likely that they won't have a clue on what causes their end of things to try to set up a PPP session with your Hyperterminal connection.
It is believed, however, that the police have a clue as to the real culprits, and that it is being prosecuted by Mr.