instability
Americannoun
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instabilities
plural
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the quality or state of being unstable; lack of stability or firmness.
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the tendency to behave in an unpredictable, changeable, or erratic manner.
emotional instability.
noun
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lack of stability or steadiness
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tendency to variable or unpredictable behaviour
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physics a fast growing disturbance or wave in a plasma
Other Word Forms
Noun Inflected Forms
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.
Vocabulary lists containing instability
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Southeast Asia - High School
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
The dot plot was originally designed to give a heads-up to the public about the Fed’s intentions in order to avoid bouts of instability in the economy.
From MarketWatch ● Sep. 15, 2026
Brent crude settled at about $106 a barrel, up 1%, as widening instability in the Middle East threatens oil supply.
From The Wall Street Journal ● Sep. 15, 2026
Iceberg calving is a normal part of the life cycle of outlet glaciers, but scientists monitor these events closely for clues about longer-term signs of instability.
From Science Daily ● Sep. 4, 2026
A major earthquake in 2015 may also have contributed to longer-term instability.
From Barron's ● Sep. 4, 2026
It was a stable instability that would endure for the rest of Howards life, which was destined to be many decades shorter than Dorothy’s.
From "Hidden Figures" by Margot Lee Shetterly
The researchers believe these swirling flows are evidence of Kelvin-Helmholtz instabilities, a familiar phenomenon in fluid dynamics.
From Science Daily ● Aug. 8, 2026
These instabilities have been a major obstacle to improving fusion performance.
From Science Daily ● Jan. 4, 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
Trax's recovery from his psychological instabilities wasn't as definitive.
From Underground by Suelette Dreyfus
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
