have got an ace up (one's) sleeve

have got an ace 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've got an ace up my sleeve for this race—my stamina. The other runners don't stand a chance! I hear that the defense attorney has got an ace up her sleeve—a new eye-witness.
See also: ace, have, sleeve, up
Farlex Dictionary of Idioms.
See also:
  • a card up (one's) sleeve
  • card up sleeve
  • have (something) up (one's) sleeve
  • have a card up your sleeve
  • have an ace up (one's) sleeve
  • have an ace up your sleeve
  • have an ace/a trick up your sleeve
  • have something up your sleeve
  • have up sleeve
  • trick up (one's) sleeve