uncertainty
/ˌən-ˈsər-tᵊn-tē/
noun
the quality or state of being uncertain : doubt
something that is uncertain
uncertainty doubt dubiety skepticism suspicion mistrust mean lack of sureness about someone or something. uncertainty may range from a falling short of certainty to an almost complete lack of conviction or knowledge especially about an outcome or result. doubt suggests both uncertainty and inability to make a decision.
noun
a principle in quantum mechanics: it is impossible to discern simultaneously and with high accuracy both the position and the momentum of a particle (such as an electron) —called also Heisenberg uncertainty principle
noun
uncertainty principle —called also Heisenberg's uncertainty principle