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

It demeans the entire nation, and adds to the instability in the world.

From Salon ● Aug. 21, 2026

Five women and three men are in the running to succeed Antonio Guterres as leader of the United Nations, which faces unprecedented global instability, wars and its own crushing budget crisis.

From Barron's ● Aug. 21, 2026

None of the works address the recent bombardments directly, although the precarious context of ongoing threat, instability and struggle can be felt in almost all of them.

From Los Angeles Times ● Aug. 20, 2026

“The sense of fear and severe anxiety has intensified, and the feeling of uncertainty and instability has grown,” he said.

From The Wall Street Journal ● Aug. 11, 2026

Every day he punched cards, punched and punched, trying to avoid instability, divergence, distortion.

From "Typical American" by Gish Jen

The researchers believe these swirling flows are evidence of Kelvin-Helmholtz instabilities, a familiar phenomenon in fluid dynamics.

From Science Daily ● Aug. 8, 2026

Kelvin-Helmholtz instabilities develop when two fluids move alongside one another at different speeds.

From Science Daily ● Aug. 8, 2026

By measuring the beam's shape and the magnetic fields it generated, the researchers were able to determine whether plasma instabilities could be strong enough to disrupt the beam's flow.

From Science Daily ● Nov. 7, 2025

The researchers reported their findings on May 11 in Nature Communications, underscoring the vast potential of machine learning and other artificial intelligence systems to quickly quash plasma instabilities.

From Science Daily ● Jun. 5, 2024

Alienists assure us that insanity is on the increase, and it is certain that modern conditions of life have favoured nervous instabilities of temperament, which express themselves in eccentricities of conduct. 

From The Vagabond in Literature by Arthur Rickett

Related Words

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