Idiom
have an ace up one's sleeve
Theme: DECEPTION
to have a secret or concealed means of accomplishing something.I think that Liz has an ace up her sleeve and will surprise us with success at the last minute.I have done all I can do. I have no idea what to do next. I don't have an ace up my sleeve, and I can't work miracles.
Slang
have an ace up one's sleeve
Theme: TRICK
tr. to have something useful in reserve; to have a special trick available. (Have got can replace have.)I still have an ace up my sleeve that you don't know about.I don't have an ace up my sleeve. If it doesn't work, it doesn't work.