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.

---

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

---

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

Adobe stock drops Monday after receiving a double downgrade from Wells Fargo, which cited worsening organic growth, executive instability, and a loss in pricing power.

From Barron's ● Oct. 12, 2026

It also often leads to housing instability, academic withdrawal, and family dissolution.

From Slate ● Oct. 8, 2026

If the older silica-poor disks and their seemingly random periods of changing infrared brightness are caused by orbital instability, the pattern would be broadly compatible with the Late Heavy Bombardment hypothesis for our solar system.

From Science Daily ● Oct. 7, 2026

"The coastline flanking the sea arch has shown signs of instability for years," NPS, which warned in 2021 that the arch would eventually crumble, said in a statement.

From BBC ● Oct. 2, 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

“We now have shocks that unleash endogenous instabilities that trigger new shocks,” she said.

From The Wall Street Journal ● Oct. 13, 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

If instead the researchers can improve the model's ability to recognize the precursors to these harmful instabilities, it could be possible to optimize the system without encountering a single edge burst.

From Science Daily ● Jun. 5, 2024

Just as the study of hysteria deals mainly with instabilities in the threshold of consciousness, so does the study of zymotic disease deal mainly with instabilities in the constitution of the blood.

From Human Personality and its Survival of Bodily Death by F. W. H. (Frederic William Henry) Myers

Random Word

Spin the wheel and learn a new word!

---

Related Words

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

---