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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 Authorities add that polluted water, marine debris, and unstable cliffs may also pose hazards, according to a webpage from the National Park Service (NPS). Anna Skinner, MSNBC Newsweek, 17 Oct. 2025 Arj thinks putting discos in your house and having all the money in the world is a pretty sweet way to exist, while Jeff’s forced to live an unstable life. Brian Truitt, USA Today, 16 Oct. 2025 Where the show’s values were once givens, almost diorama labels, now they’re presented as more fugitive and unstable, what its characters would hope the world to be. Jackson McHenry, Vulture, 16 Oct. 2025 Antioxidants help fight free radicals, which are unstable molecules that can damage cells in the body. Brittany Lubeck, Verywell Health, 14 Oct. 2025 See All Example Sentences for unstable
Recent Examples of Synonyms for unstable
Adjective
  • The shock to Hal and Kate’s equilibrium, already unsteady to begin with, is even more rewarding.
    Alison Herman, Variety, 16 Oct. 2025
  • The senator seemed unsteady, but got up and kept walking with the help of his detail.
    Lauren Peller, ABC News, 16 Oct. 2025
Adjective
  • With a roster that includes Margot Robbie, Miles Teller and Brooke Shields, Ullman says tariff anxiety shoehorned into an already volatile market and tense political climate has pushed clients to be far more conservative.
    Trey Williams, HollywoodReporter, 22 Oct. 2025
  • Gold has seen historic gains in 2025, its more-than-50% surge surpassing previous volatile periods such as after the September 11 attacks, the 2008 financial crisis or even the Covid-19 pandemic.
    John Liu, CNN Money, 22 Oct. 2025
Adjective
  • Week 7 gives us another chance to form impassioned opinions on precarious outcomes.
    Steven Louis Goldstein, New York Times, 17 Oct. 2025
  • Due to the Jenga-like tower of precarious issues, the act of parenting becomes more arduous and challenging for Linda — a chore even.
    Randy Myers, Mercury News, 16 Oct. 2025
Adjective
  • But Amorim, who is approaching 12 months in charge of the club, acknowledges that football is an unpredictable industry and results will influence the mood among United’s hierarchy.
    Laurie Whitwell, New York Times, 17 Oct. 2025
  • The United States maintains overwhelming technological superiority but with increasingly unpredictable commitments.
    Eleanor Pringle, Fortune, 16 Oct. 2025
Adjective
  • After Florida State and Clemson fought for an uneven share of ACC revenue, a Georgia Tech versus Virginia championship game just feels right.
    Stewart Mandel, New York Times, 19 Oct. 2025
  • Southern live oaks draped in Spanish moss that tower and twist over city squares, Neoclassical Antebellum architecture, gas lamps that flicker over uneven cobblestone paths, and a humid subtropical climate that hangs heavy in the air.
    Nicole Kliest, Vogue, 18 Oct. 2025
Adjective
  • The journey to this point had been rocky.
    The Athletic NBA Staff, New York Times, 17 Oct. 2025
  • The ad battle comes on the heels of a rocky moment for Virginia Democrats, who were forced to confront violent text messages their attorney general nominee, Jay Jones, sent in 2022, comments that sparked bipartisan criticism and complicated the party’s message heading into November.
    Samantha-Jo Roth, The Washington Examiner, 16 Oct. 2025
Adjective
  • Terry Francona The manager did not get his team to a victory in the unbalanced series, but his ability to return from a year off from the game to deliver a playoff spot to the Red for the first time since 2020 is impressive.
    Tim Crowley, MSNBC Newsweek, 3 Oct. 2025
  • If your microbiome is unbalanced between beneficial and harmful microbes, probiotics can help introduce healthy microbes back into your body.
    Isabel Vasquez RD LDN, Health, 1 Oct. 2025

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Cite this Entry

“Unstable.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/unstable. Accessed 23 Oct. 2025.

More from Merriam-Webster on unstable

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