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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 Fixed a bug where Dormant Power might not appear upon defeating an enemy under unstable network conditions. Oliver Brandt, MSNBC Newsweek, 10 Sep. 2025 Should Iran become more unstable, the resulting turmoil could be felt across the region. David Mednicoff, The Conversation, 9 Sep. 2025 Other challenges can include the loss of institutional knowledge when experienced workers leave and an unstable workforce that undermines client confidence. Jasmin Malik Chua, Sourcing Journal, 8 Sep. 2025 The situation at home was unstable. Rebecca Mead, New Yorker, 8 Sep. 2025 See All Example Sentences for unstable
Recent Examples of Synonyms for unstable
Adjective
  • But Sky Sports has since reported that Ashworth thought Amorim was the wrong choice and would cause more disruption to an already unsteady ship.
    Zak Garner-Purkis, Forbes.com, 17 Sep. 2025
  • Frazier came out of his corner in the 14th all but blind, rocking on unsteady legs.
    Vann R. Newkirk II, The Atlantic, 16 Sep. 2025
Adjective
  • In such a volatile climate, remarks that appear dismissive or insensitive can end careers, as networks and broadcasters face mounting pressure to act.
    Martha McHardy Shane Croucher, MSNBC Newsweek, 18 Sep. 2025
  • Relief pitching might be among the more volatile areas if not the department offering the most volatility.
    Larry Fleisher, Forbes.com, 18 Sep. 2025
Adjective
  • While Benfica made a winning start and trounced local rivals Sporting 3-0 in December 2000, Mourinho’s position became precarious after Joao Vale e Azevedo, who had appointed him, was replaced as president by Manuel Vilarinho.
    Dan Cancian, Forbes.com, 19 Sep. 2025
  • The series Witsec follows a DOJ lawyer and a hardened mob hitman, both fed up with the corrupt institutions around them, who form a precarious alliance to convict criminal titans and save lives in the rogue origins of the Witness Protection Program.
    Rosy Cordero, Deadline, 19 Sep. 2025
Adjective
  • How to survive the fast food temptation Life is unpredictable.
    Michiko Tomioka, CNBC, 19 Sep. 2025
  • Energy costs remain unpredictable, and regulators are raising the bar.
    Ron Schmelzer, Forbes.com, 19 Sep. 2025
Adjective
  • Conventional cooling systems often rely on cold plates that offer indirect contact with battery cells, which can result in uneven temperature distribution.
    Aman Tripathi, Interesting Engineering, 14 Sep. 2025
  • Polishing and setting diamonds on uneven surfaces is a rare skill and Chopard does it all in-house.
    Thomas Waller, Footwear News, 13 Sep. 2025
Adjective
  • The Future At NASA, the future of exoplanet science will emphasize finding rocky planets similar to Earth and studying their atmospheres for biosignatures — any characteristic, element, molecule, substance, or feature that can be used as evidence of past or present life, says the space agency.
    Bruce Dorminey, Forbes.com, 19 Sep. 2025
  • This rocky cliff overlooking the valley is accessible through the 3-mile Whitaker Point Trail.
    Katie Strasberg Rousso, Southern Living, 19 Sep. 2025
Adjective
  • That’s going to wear thin quickly because the friendship becomes unbalanced and remains so.
    R. Eric Thomas, Mercury News, 13 Sep. 2025
  • Have unbalanced and excessive cortisol?
    Margaux Anbouba, Vogue, 11 Sep. 2025

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Cite this Entry

“Unstable.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/unstable. Accessed 21 Sep. 2025.

More from Merriam-Webster on unstable

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