up (one's) sleeve(redirected from up her sleeve)
up (one's) sleeve
Of a plan or advantage, kept 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 My stamina is the ace up my sleeve for this race—the other runners don't stand a chance! I've got a few tricks up my sleeve if he decides to pursue legal action against me.