uncertainty

The word “uncertainty” means a state of doubt or lack of sureness about something. In plain terms, not knowing for sure — either in everyday life or as a technical measure of how precise a number is.

“Uncertainty” is pronounced uhn-SUR-tuhn-tee (/ʌnˈsɝtənti/ in IPA).

Here is “uncertainty” used in a sentence: “The uncertainty over her diagnosis kept the whole family on edge.”

Words with a similar meaning to “uncertainty” include uncertainness.

The opposite of “uncertainty” — its antonyms — are certainty and closure.

“Uncertainty” is a noun.

The word “uncertainty” comes from Middle English. From Middle English uncerteynte, from un- + certainty.

“Uncertainty” is a fairly common word in modern English, usually learned at around the B1 level.

Doubt usually implies leaning toward disbelief about a specific claim or person, while uncertainty is a broader state of simply not being sure either way. You can feel uncertainty about the future without doubting anyone in particular; doubt tends to have a target.

In economics and decision theory, risk describes situations where the outcomes are unknown but their probabilities can be estimated, while uncertainty describes situations where even the probabilities are unknown. In everyday English, though, uncertainty simply means a lack of sureness about something.

Yes. When uncertainty refers to the general state of doubt it is uncountable, but individual unknown factors can be counted, as in "the project still faces several uncertainties." Both uses are fully standard.