instability

noun

in·​sta·​bil·​i·​ty ˌin(t)-stə-ˈbi-lə-tē 

: the quality or state of being unstable

especially : lack of emotional or mental stability

Synonyms of instability

• unsteadiness
• precariousness
• unstableness
• insecurity

Examples of instability in a Sentence

Investors are worried about the current instability of the stock market.

The patient has a history of emotional instability.

Recent Examples on the Web

The instability of recent years, mixed with the failure of the Russian forces brought in following Mali’s rejection of French and EU troops, means the near term outlook is bleak. —Ulf Laessing, semafor.com, 30 Apr. 2026

While instability is lower than earlier this week, don't rule out a few rumbles of thunder and isolated pockets of small hail in stronger cells. —Nelly Carreño, CBS News, 30 Apr. 2026

Morrison acknowledged the broader toll of recent instability. —Walker Armstrong, San Diego Union-Tribune, 30 Apr. 2026

Over the past several years, firms have faced a rapid succession of shocks, from inflation and rising interest rates to recurring fears of recession and geopolitical instability. —Jeffrey Sonnenfeld, Fortune, 29 Apr. 2026

Word History

First Known Use

15th century, in the meaning defined above

Rhymes for instability

• affability
• audibility
• bistability
• capability
• changeability
• contractility
• credibility
• culpability
• disability
• disutility
• durability
• fallibility

Kids Definition

instability

noun

in·​sta·​bil·​i·​ty ˌin(t)-stə-ˈbil-ət-ē 

: the quality or state of being unstable

Medical Definition

instability

noun

in·​sta·​bil·​i·​ty ˌin(t)-stə-ˈbil-ət-ē 

plural instabilities

: the quality or state of being unstable

especially : lack of emotional or mental stability