have (something) up (one's) sleeve

To have a secret plan, idea, or advantage that can be utilized if and when it is required. A reference to cheating at a card game by hiding a favorable card up one's sleeve. I have a few tricks up my sleeve if he decides to pursue legal action against me. She has all the details of their unscrupulous business practices up her sleeve if they ever try to fire her.

Fig. to have a secret or surprise plan or solution (to a problem). (Alludes to cheating at cards by having a card hidden in one's sleeve.) I've got something up my sleeve, and it should solve all your problems. I'll tell you what it is after I'm elected. The manager has an ace up her sleeve. She'll surprise us with it later.

COMMON If you have something up your sleeve, you have a secret idea or plan which you can use to gain an advantage over other people. Paterson had another plan up his sleeve, however. If that failed, he had one final trick up his sleeve. We would wait to see what Bill had up his sleeve. Note: You can also just talk about something, such as a plan or a trick, that is up someone's sleeve. The manager insisted his team will use every trick up their sleeve to defeat their rivals. Note: The expressions have an ace up your sleeve and have a card up your sleeve mean the same. He always seems to have an ace up his sleeve to deal with these kinds of situations. Even his critics admit that he seems always to have a card up his sleeve. Note: If someone wanted to cheat at cards, they could hide a good card up their sleeve to use at an appropriate time.