Definition of unstablenext
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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 Born in Memphis in 1941, Maurice endured an unstable childhood marked by separation and loss. Jordan Runtagh, PEOPLE, 11 June 2026 However, their performance has been hindered by unstable zinc deposition and unwanted reactions between zinc electrodes and water during charging and discharging. Neetika Walter, Interesting Engineering, 10 June 2026 Culverts can become unstable and unsafe. Nc Weather Bot, Charlotte Observer, 10 June 2026 Heavy, unstable liquids can also be stored without the massive financial and environmental costs of, for example, deep-freeze air freight. Elsa Ohlen, CNBC, 9 June 2026 See All Example Sentences for unstable
Recent Examples of Synonyms for unstable
Adjective
  • Oil prices have been unsteady as hopes rise and fade that the United States and Iran can reach a deal to reopen the Strait of Hormuz.
    Stan Choe, Los Angeles Times, 9 June 2026
  • Fledglings can look unsteady or weak, but the parents are nearby for protection.
    Blythe Copeland, Martha Stewart, 6 June 2026
Adjective
  • Mario Tama | Getty Images Global stock markets remain volatile amid uncertainty in the Middle East and a focus on artificial intelligence stocks.
    TipRanks.com Staff, CNBC, 7 June 2026
  • But beyond this picturesque scene, there is a volatile combination of brutal rebel violence and a burgeoning Ebola outbreak.
    Gabrielle Emanuel, NPR, 6 June 2026
Adjective
  • In some studies, gloves not changed between tasks had higher bacterial counts and could transfer germs just as easily as ungloved hands, underscoring the need for frequent changing and proper hand hygiene.
    Evan Moore December 19, Charlotte Observer, 19 Dec. 2025
Adjective
  • In a recent rapid assessment in India, where tariffs rose to as much as 50 percent last year, AFWA found that suppliers absorbing cost increases passed them on to their employees through rising workloads, precarious wages and other hallmarks of deepening exploitation.
    Jasmin Malik Chua, Footwear News, 10 June 2026
  • In the political landscape that Tate helped create, women hold an increasingly precarious position.
    Heidi Blake, New Yorker, 8 June 2026
Adjective
  • The two men emerged from a crowded field of candidates in the most unpredictable governor’s race in more than a quarter of a century.
    Seema Mehta, Los Angeles Times, 9 June 2026
  • Prices are subject to rapid, unpredictable changes due to factors like, but not limited to, supply/demand, weather, and geopolitical events.
    USA TODAY, USA Today, 9 June 2026
Adjective
  • These Black Diamond poles help take pressure off knees and joints during steep descents while providing extra stability on uneven terrain.
    Francesca Krempa, Travel + Leisure, 11 June 2026
  • His central finding is that task-level productivity gains are real but do not automatically translate to firm-level or economy-wide effects — and that the historical analogy to electrification suggests transformation will be slow, uneven, and dependent on complementary investment.
    Mayra Rodriguez Valladares, Forbes.com, 11 June 2026
Adjective
  • Approved by George Washington and first illuminated in 1791, the lighthouse predates Maine’s statehood and remains an active aid to navigation on the rocky coast of Maine.
    USA TODAY Network, USA Today, 10 June 2026
  • After a rocky election night that showed the tax lagging, supporters claimed victory Tuesday after the latest vote tally pushed Measure ER further over the 50% margin needed to pass.
    Rebecca Ellis, Los Angeles Times, 10 June 2026
Adjective
  • This is a recurring injury for Smith, who has missed five of the last nine games due to varying levels of discomfort in his calf.
    Julia Poe, Chicago Tribune, 23 Feb. 2026
  • 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

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Cite this Entry

“Unstable.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/unstable. Accessed 13 Jun. 2026.

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