Uncertainty (noun)

1. The quality or state of being uncertain, unsure, or doubtful.
2. An instance of this.

Origin:

Late middle english, from uncertain + -ty.

Examples:

1. There was a high degree of uncertainty about the outcome of the election.
2. The uncertainty of the situation made it difficult to plan ahead.
3. The investors are cautious because of the uncertainty in the stock market.
4. The uncertainty of the future is what keeps her up at night.
5. The company faced many challenges and uncertainties in the first year.