1. not have a clue : 不懂, 一无所知;
名词
1. 线索;提示
A clue to a problem or mystery is something that helps you to find the answer to it.
2. (破案)线索
A clue is an object or piece of information that helps someone solve a crime.
3. (纵横填字游戏的)提示语,解答提示
A clue in a crossword or game is information which is given to help you to find the answer to a question.
4. 不知道;一无所知
If you haven't a clue about something, you do not know anything about it or you have no idea what to do about it.