Vicissitude (noun)

1. The state or quality of being subject to change or variation; instability.
2. The regular or cyclical change of circumstances or fortune, typically one that is unwelcome or unpleasant.

Origin:

From the latin word "vicissitudo" meaning "change".

Examples:

1. He was prepared for the vicissitudes of life.
2. The vicissitudes of the weather made it hard to plan outdoor activities.
3. The company's success was affected by the vicissitudes of the economy.
4. She faced the vicissitudes of life with a positive attitude.
5. The vicissitudes of love and relationships are well-known.