quality - an essential and distinguishing attribute of something or someone; "the quality of mercy is not strained"--Shakespeare

doubt, doubtfulness, dubiousness, question - uncertainty about the truth or factuality of existence of something; "the dubiousness of his claim"; "there is no question about the validity of the enterprise"

indefiniteness, indefinity, indeterminacy, indeterminateness, indetermination - the quality of being vague and poorly defined

unpredictability - lacking predictability

improbability, improbableness - the quality of being improbable

fortuitousness - the quality of happening accidentally and by lucky chance

cognitive state, state of mind - the state of a person's cognitive processes

arriere pensee, mental reservation, reservation - an unstated doubt that prevents you from accepting something wholeheartedly

distrust, mistrust, suspicion, misgiving - doubt about someone's honesty

disbelief, incredulity, mental rejection, skepticism - doubt about the truth of something

indecision, indecisiveness, irresolution - doubt concerning two or more possible alternatives or courses of action; "his indecision was only momentary but the opportunity was lost"

suspense - an uncertain cognitive state; "the matter remained in suspense for several years"