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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 Rigid robots are prone to damage in unstable, cramped environments and are expensive to repair. Kurt Knutsson, FOXNews.com, 28 Apr. 2025 Remember: Antioxidants can slow aging and prevent skin damage caused by unstable molecules called free radicals. Danielle Jackson, Glamour, 28 Apr. 2025 Polyphenols neutralize unstable, harmful molecules (free radicals) in the body that contribute to inflammation and cell damage. Amy Brownstein, Ms, Rdn, Verywell Health, 25 Apr. 2025 The twinkling effect is caused by the unstable state of the air through which a star's light must pass to reach our eyes. Joe Rao, Space.com, 25 Apr. 2025 See All Example Sentences for unstable
Recent Examples of Synonyms for unstable
Adjective
  • Her hands became too unsteady after 2000 to continue drawing.
    Hilarie M. Sheets, New York Times, 4 Apr. 2025
  • Something long and meandering like this: For the next four years, the United States will be an unpredictable, unsteady global superpower run by a fascist oligarchy, in which the people’s representatives cater to a madman’s whim.
    Eli Grober, The New Yorker, 24 Mar. 2025
Adjective
  • Some of the problems are caused by a volatile economic landscape.
    Jack Kelly, Forbes.com, 10 May 2025
  • Indian authorities have evacuated tens of thousands of civilians from villages near the volatile frontier.
    Rajesh Roy, Chicago Tribune, 9 May 2025
Adjective
  • This leaves the new Laptop in a somewhat precarious position: just $100 cheaper than the flagship Surface Laptop, with a noticeable downgrade in screen size and resolution and a small downgrade in performance.
    ArsTechnica, ArsTechnica, 6 May 2025
  • After a couple of Shai Gilgeous-Alexander free throws gave the Thunder that precarious three-point lead with 13.2 left, the Nuggets and Nikola Jokic breathing heavy down Oklahoma City’s neck, guard Caruso took a foul on Jokic.
    Luca Evans, Denver Post, 6 May 2025
Adjective
  • Some British places are utterly unpredictable to pronounce.
    Maureen O'Hare, CNN Money, 3 May 2025
  • Steering the cart is an obvious responsibility of her role, but navigating the course mentally is just as important due to the unpredictable players on the field.
    Skyler Caruso, People.com, 2 May 2025
Adjective
  • John’s piano and vocals, thankfully, were front and center, and did not suffer from uneven mixing.
    George Varga, San Diego Union-Tribune, 10 May 2025
  • This can be seen when the gap between the doors is too small, too large, or uneven.
    Timothy Dale, Better Homes & Gardens, 8 May 2025
Adjective
  • As the tension builds, Hunter pushes his client to consider cutting ties with unnecessary people on his payroll, even throwing in a mention of LeBron James, with whom Smith has famously had a rocky relationship in the past.
    Amber Corrine, VIBE.com, 9 May 2025
  • But the end of the former chancellor’s tenure had been rocky.
    Daniel Miller, Los Angeles Times, 8 May 2025
Adjective
  • A lot of casuals were turned off by the entire extraction shooter concept of losing loot or unbalanced fights.
    Paul Tassi, Forbes.com, 3 May 2025
  • Your choice comes after years of trying to make things work despite the unbalanced responsibilities and disrespect.
    Anna Pulley, Chicago Tribune, 30 Apr. 2025

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Cite this Entry

“Unstable.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/unstable. Accessed 17 May. 2025.

More from Merriam-Webster on unstable

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