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Synonym Chooser

How does the adjective unstable differ from other similar words?

Some common synonyms of unstable are capricious, fickle, inconstant, and mercurial. While all these words mean "lacking firmness or steadiness (as in purpose or devotion)," unstable implies an incapacity for remaining in a fixed position or steady course and applies especially to a lack of emotional balance.

too unstable to hold a job

When can capricious be used instead of unstable?

The synonyms capricious and unstable are sometimes interchangeable, but capricious suggests motivation by sudden whim or fancy and stresses unpredictability.

an utterly capricious critic

When would fickle be a good substitute for unstable?

The words fickle and unstable can be used in similar contexts, but fickle suggests unreliability because of perverse changeability and incapacity for steadfastness.

performers discover how fickle fans can be

When is inconstant a more appropriate choice than unstable?

The words inconstant and unstable are synonyms, but do differ in nuance. Specifically, inconstant implies an incapacity for steadiness and an inherent tendency to change.

an inconstant friend

When could mercurial be used to replace unstable?

Although the words mercurial and unstable have much in common, mercurial implies a rapid changeability in mood.

made anxious by her boss's mercurial temperament

Example Sentences

Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Recent Examples of unstable Pecans Pecans are loaded with polyphenolic compounds, especially ellagic acid and flavonoids, which help neutralize free radicals, unstable molecules that lead to cell damage. Lauren Panoff, Verywell Health, 30 Oct. 2025 Petrol price increases and the naira currency’s unstable exchange rate to the dollar had driven inflation beyond 30% last year, aggravating a cost of living crisis. Alexander Onukwue, semafor.com, 30 Oct. 2025 You might be born into a politically unstable country through no fault of your own or unable to afford to move out of an area with poor air quality. Lindsey Leake, CNN Money, 30 Oct. 2025 Obviously, our times are very unstable and it’s all polarized and people have a lot of anxiety, more than ever probably. Kate Erbland, IndieWire, 30 Oct. 2025 See All Example Sentences for unstable
Recent Examples of Synonyms for unstable
Adjective
  • Where Aytaç was large but poised, Abdi was insubstantial, scrawny, and unsteady on his feet.
    David Wingrave, Harpers Magazine, 24 Oct. 2025
  • If something feels unsteady or on shaky ground, it will be revealed — not to break you, but to rebuild something stronger.
    Valerie Mesa, PEOPLE, 22 Oct. 2025
Adjective
  • First, the electrodes and electrolytes are adjusted to handle high temperatures, specifically replacing the volatile liquid electrolyte used in traditional Li batteries.
    Mrigakshi Dixit, Interesting Engineering, 5 Nov. 2025
  • Taking the long view Many finance leaders remain cautious, viewing bitcoin as too volatile—especially recently—compared to traditional assets.
    Sheryl Estrada, Fortune, 4 Nov. 2025
Adjective
  • But Poverty Never Left Me Almost every aspect of our life was precarious then.
    Stephanie Land, Time, 30 Oct. 2025
  • China is in a far more precarious state, mostly due to preexisting problems, but the new trade agreement is unlikely to move the dial much for either of the world’s two largest economies.
    Elisabeth Buchwald, CNN Money, 30 Oct. 2025
Adjective
  • With unpredictable twists and emotions running high, this Halloween is especially chaotic, and Mutable signs — Gemini, Virgo, Sagittarius and Pisces — can't imagine what's in store.
    Valerie Mesa, PEOPLE, 31 Oct. 2025
  • Predicting something that has becoming increasingly unpredictable is an impossible task, but here’s a look at how the shutdown could ripple through critical avenues of everyday life.
    Alicia Wallace, CNN Money, 31 Oct. 2025
Adjective
  • The early days of the season have been decidedly uneven.
    Allan Mitchell, New York Times, 2 Nov. 2025
  • Special features include their grippy Vibram outsoles, cushiony FloatPro Foam pods, and extra underfoot protection against rocks and uneven terrain.
    Olivia Young, Travel + Leisure, 1 Nov. 2025
Adjective
  • The 40 minute round-trip rolls up the Red Clay Valley, with unobstructed views of moonlit fields, rocky cuts and creek banks.
    Brandee Gruener, Southern Living, 31 Oct. 2025
  • Combined with a rocky job market, that’s led young people to find hope in the stock market.
    Sasha Rogelberg, Fortune, 29 Oct. 2025
Adjective
  • Even within a single day, temporary weight shifts are common and are often due to varying levels of fluid retention.
    Lauren O'Connor, Health, 22 Oct. 2025
Adjective
  • Your height is determined by a combination of genes (traits passed down in families) and environmental factors, such as an unbalanced diet, malnutrition, economic status, and certain conditions.
    Mark Gurarie, Health, 1 Nov. 2025
  • These high rates compound the risks tied to an unbalanced grid.
    Lora Myers, Oc Register, 28 Oct. 2025

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Cite this Entry

“Unstable.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/unstable. Accessed 6 Nov. 2025.

More from Merriam-Webster on unstable

Last Updated: - Updated example sentences
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