1. (n.) The quality or state of being uncertain.

2. (n.) That which is uncertain; something unknown.

Pyrrhonism accidentality actuarial calculation adventitiousness agitation ambiguity ambiguousness ambitendency ambivalence amphibology anxiety apprehension arrhythmia bleariness blur blurriness bother break brokenness calculated risk capriciousness casualness chance chanciness change of mind changeableness choppiness cliff-hanging complexity of meaning concern criticalness darkness defocus delicacy destiny desultoriness deviability diffidence dimness disconnectedness discontinuity disquiet distress distrust distrustfulness double entendre double meaning double reference double-mindedness doubt doubtfulness dread dubiety dubiousness eccentricity equivocacy equivocality equivocalness erraticism erraticness expectant waiting faintness fate feebleness fence-sitting fence-straddling fibrillation fickleness filminess fitfulness fits and starts flier flightiness fluctuation flukiness fogginess fortuitousness fortuity fortune freakishness fuzziness gamble good fortune good luck half-belief half-visibility hap happenstance happy chance hazard hazardousness haziness heedless hap hesitation how they fall impulsiveness incertitude inconsistency inconstancy indecision indecisiveness indefiniteness indeterminacy indeterminateness indistinctness indistinguishability infirmity of purpose insecurity instability intermittence irony irregularity irresolution jerkiness law of averages leeriness levels of meaning lot low profile luck mercuriality misdoubt misgiving mistiness mistrust mistrustfulness moira moodiness mugwumpery mugwumpism multivocality opportunity paleness paronomasia patchiness perilousness perturbation pessimism play plunge polysemousness polysemy precariousness principle of indeterminacy probability problematicness punning query question random sample reserve restlessness richness of meaning risk riskiness roughness run of luck salt scruple scrupulousness second thoughts self-doubt semivisibility serendipity shadow of doubt shadowiness shakiness shiftiness skepticalness skepticism slipperiness soft focus spasticity speculation sporadicity sporadicness spottiness stagger statistical probability suspense suspicion suspiciousness sword of Damocles tergiversation the breaks theory of probability ticklish business ticklishness total skepticism totteriness touchiness trouble uncertainty principle unclearness undecidedness undependability undeterminedness uneasiness unevenness unfixedness unhealthiness unmethodicalness unplainness unpredictability unreliability unsafeness unsettledness unsettlement unsoundness unstableness unsteadfastness unsteadiness unsureness unsystematicness untrustworthiness vague appearance vagueness variability variation variety venture waiting wantonness wariness waywardness weakness whatever comes whimsicality wobble wonder worry