(n.) The act of vacillating; a moving one way and the other; a wavering.

alternation capriciousness chance chanciness changeableness dallying demurral dillydallying equivocation erraticism erraticness fickleness fluctuation frequency frequency band frequency spectrum harmonic motion hesitancy hesitation incalculability incertitude indecision indecisiveness indemonstrability indeterminacy indetermination indeterminism irresolution libration luck nutation oscillation pendulation periodicity randomness resonance resonance frequency seesawing shifting shilly-shally shilly-shallying shuffling suspense suspensefulness teeter-tottering teetering tottering unaccountability uncertainness uncertainty uncertainty principle undecidedness undeterminedness unforeseeableness unpredictability unprovability unsureness unverifiability variation vibrancy vibratility vibration vicissitude wavering whimsicality wobbling