1. the quality or state of being unstable; lack of stability or steadiness
Usage: formal; less common than ‘instability’

Examples

• The unstableness of the old bridge made it dangerous to cross.
• Political unstableness in the region affected international trade.
• The patient’s emotional unstableness required careful monitoring.
• Economic unstableness led to widespread uncertainty among investors.
• The unstableness of the chemical compound made it difficult to store safely.