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