keep (something) up (one's) sleeve(redirected from keep up their sleeves)
keep (something) up (one's) sleeve
To keep something, such as a plan or advantage, in secret so it 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. What the other runners don't know is that I've kept an ace up my sleeve for this race—my stamina. I've been keeping a few tricks up my sleeve if he decides to pursue legal action against me.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
have/keep something up your ˈsleeve(informal) have a good idea, plan or piece of information which you are not telling anyone about now, but which you intend to use later: John was smiling to himself all through the meeting; I’m sure he’s got something up his sleeve.
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