not hold breath
not hold your breath
to not expect something to happen quickly She wants the company to apologize for damaging her reputation, but she isn't holding her breath.
Usage notes: often used in the form don't hold your breath: If you're waiting for the next big cut in computer prices to buy that powerful new machine, don't hold your breath.
Etymology: based on the idea that it will take longer for the thing you are waiting for to happen than the amount of time you can hold you breath (stop breathing)