ace up (one's) sleeve

(redirected from ace up sleeve)
Also found in: Dictionary, Thesaurus, Medical, Legal, Encyclopedia.

ace up (one's) sleeve

A secret advantage. My stamina is the ace up my sleeve for this race—the other runners don't stand a chance! The defense attorney waited for just the right time to play the ace up her sleeve—a new eye-witness.
See also: ace, sleeve, up