instability

American  

[in-stuh-bil-i-tee] / ˌɪn stəˈbɪl ɪ ti /

noun

instabilities plural

1. the quality or state of being unstable; lack of stability or firmness.

2. the tendency to behave in an unpredictable, changeable, or erratic manner.

   emotional instability.

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instability British  

/ ˌɪnstəˈbɪlɪtɪ /

noun

1. lack of stability or steadiness

2. tendency to variable or unpredictable behaviour

3. physics a fast growing disturbance or wave in a plasma

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Other Word Forms

Noun Inflected Forms

• instabilities
  plural

Etymology

Origin of instability

1375–1425; late Middle English instabilite < Latin instabilitās. See in- ³, stability

Explanation

Instability is the quality of not being stable, balanced, or predictable. If you've ever walked out onto a diving board, you've probably noticed its instability — meaning the board bends and bounces as you move. Instability comes from the Middle French word instabilite, meaning "unsteadiness." Instability can refer to objects that are not stable, but it can also describe unpredictable situations or relationships. For example, you might hear people talk about economic instability. Or if your behavior at school grows erratic and unpredictable, you might be asked to speak to a therapist about your psychological instability.

Example Sentences

See Examples For:

instability instabilities

That certainly applies to Haiti, which is enduring tremendous hardship and instability.

From Slate ● Jul. 28, 2026

"We need to work together to address issues like conflict, instability, governance failures, poverty and social discord."

From Barron's ● Jul. 27, 2026

Weeks before falling severely ill, he consulted the tool about recurring dizzy spells and "bouts of blood pressure instability".

From BBC ● Jul. 23, 2026

Golding is writing about the instability of the self, after all, and his prose enacts that instability: shifting perspectives and uncertain ground, relieved by moments of sudden, disquieting clarity.

From The Wall Street Journal ● Jul. 22, 2026

Blandly telling him that I kept my hair long to avoid confusion with American Air Force personnel proved my mental instability.

From "Double Helix" by James D. Watson

These instabilities have been a major obstacle to improving fusion performance.

From Science Daily ● Jan. 4, 2026

These persistent instabilities can affect everything from uplift and erosion to inland volcanic patterns, even in regions considered geologically stable.

From Science Daily ● Nov. 25, 2025

Combining high-speed synchrotron X-ray imaging, theoretical analysis and numerical simulation, the researchers revealed the defect mitigation mechanisms, which involve phenomena that reduce instabilities in the laser powder bed fusion process.

From Science Daily ● Nov. 22, 2024

"The instabilities that we expect in Antarctica could be very different, and we can now capture those differences, using this model."

From Science Daily ● Jun. 3, 2024

It has experienced almost continuous conflict between nations, internal instabilities in many countries, and regional rivalries, combined with very rapid economic and social change.

From State of the Union Address by Carter, Jimmy

Related Words

• anxiety
• fluctuation
• insecurity
• uncertainty
• volatility
• vulnerability
• weakness