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 Why invest in unstable corridors? Dylan Spencer, The Conversation, 4 Mar. 2026 The airspace closures are expected to hold up all cargo entering Iranian borders as conditions throughout the country remain unstable. Glenn Taylor, Sourcing Journal, 3 Mar. 2026 Remaining passengers on affected vessels also hope to eventually disembark and fly home, but with the geopolitical situation fluid and unstable, return dates are uncertain. Francesca Street, CNN Money, 3 Mar. 2026 What began as a precision event evolves into unstable escalation. Robert A. Pape, Mercury News, 3 Mar. 2026 See All Example Sentences for unstable
Recent Examples of Synonyms for unstable
Adjective
  • Usually when the economy is unsteady and the job market is weakening, the Federal Reserve cuts interest rates to give things a boost.
    Stan Choe, Los Angeles Times, 6 Mar. 2026
  • Lusti and Morrison made their first attempt in 2023 alongside big-mountain skier Tanner McNutt, but avalanches and unsteady snowpack turned the trio back from the summit.
    Frederick Dreier, Outside, 3 Mar. 2026
Adjective
  • Asian shares slide in a volatile session.
    Nasteho Said, Bloomberg, 9 Mar. 2026
  • The dismal report comes at a volatile time for the economy, as the war in Iran risks reigniting inflation.
    J.D. Capelouto, semafor.com, 8 Mar. 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
  • Most of these workers—known as candangos—lived in precarious conditions.
    Sophia La Banca, JSTOR Daily, 11 Mar. 2026
  • For a player built around explosive movement and a punishing serve, the margin can feel precarious.
    Douglas Robson, Los Angeles Times, 9 Mar. 2026
Adjective
  • Strengthening the layers Epoch 2 solves the problem of unpredictable missile paths by using high-tech heat sensors and laser communication.
    Mrigakshi Dixit, Interesting Engineering, 11 Mar. 2026
  • Revenue hinges on capital gains from investments, bonuses to executives and windfalls from new stock offerings, all of which are grossly unpredictable.
    Seema Mehta, Los Angeles Times, 10 Mar. 2026
Adjective
  • Heating elements must survive high temperatures, constant airflow and uneven heat distribution.
    Aamir Khollam, Interesting Engineering, 6 Mar. 2026
  • But employer coverage of obesity drugs remains uneven due to high costs, leaving roughly half of people with commercial insurance unable to start or stay on treatment, Lilly said in a release.
    Annika Kim Constantino, CNBC, 5 Mar. 2026
Adjective
  • But over this rocky, treacherous stretch of coastline, its beam is shining once again.
    Los Angeles Times, Los Angeles Times, 11 Mar. 2026
  • For fashion, the Fall/Winter 2026 season arrived at a moment of heightened uncertainty, as wholesale continues its rocky reset and geopolitical uncertainty remains high.
    Madeleine Schulz, Vogue, 10 Mar. 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 12 Mar. 2026.

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