Contingency (noun)

1. A future event or circumstance that is possible but cannot be predicted with certainty.
2. A provision for an unforeseen event or circumstance.
3. An amount of money that is set aside for a specific purpose or as a reserve.

Origin:

From latin contingentia ('a happening, event'), from contingere ('to touch, befall, happen').

Examples:

1. The company has a contingency plan in case of a natural disaster.
2. We need to prepare for all possible contingencies.
3. The insurance policy includes a contingency fund for unexpected expenses.
4. The wedding planner had a contingency budget in case of any last-minute changes.