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

Heightened instability in the Middle East is also pushing up costs for shipping in the Red Sea.

From The Wall Street Journal ● Aug. 26, 2026

“There’s just kind of a sense of instability and a little bit of ‘here we go again,’” she said.

From Los Angeles Times ● Aug. 25, 2026

Aggressive expansions typically come with plenty of risk: an immediate strain on resources, profit instability, and possibly outgrowing the existing business model.

From Slate ● Aug. 24, 2026

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

From Salon ● Aug. 21, 2026

The Soviets quickly caught on to the emotional distress and instability of their prized secret agent.

From "Spies: The Secret Showdown Between America and Russia" by Marc Favreau

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

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

However, the high-confinement mode has historically come hand-in-hand with instabilities at the plasma's edge, a challenge that has required fusion researchers to find creative workarounds.

From Science Daily ● Jun. 5, 2024

When they possess a fixed staff of teachers they are not, of course, liable to the instabilities which at present beset the Harvard Annex.

From The Teacher Essays and Addresses on Education by Alice Freeman Palmer

Related Words

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