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

When economic gains are concentrated and social costs ignored, instability follows. —Chicago Tribune, 14 May 2026

Trump has faced growing domestic pressure over rising energy prices tied to instability in the Middle East and shipping threats near the Strait of Hormuz. —Efrat Lachter, FOXNews.com, 14 May 2026

Forecasters also note a small tornado threat, especially where instability and wind shear overlap. —Brandi D. Addison, USA Today, 14 May 2026

On Iran, neither Washington nor Beijing wants the prolonged instability in global energy markets that the war and the subsequent wobbly cease-fire have caused. —Vivian Salama, The Atlantic, 14 May 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