mer·​cu·​ri·​al | \ (ˌ)mər-ˈkyu̇r-ē-əl How to pronounce mercurial (audio) \

Definition of mercurial

 (Entry 1 of 2)

1 : of, relating to, or born under the planet Mercury
2 : having qualities of eloquence, ingenuity, or thievishness attributed to the god Mercury or to the influence of the planet Mercury
3 : characterized by rapid and unpredictable changeableness of mood a mercurial temper
4 : of, relating to, containing, or caused by mercury



Definition of mercurial (Entry 2 of 2)

: a pharmaceutical or chemical containing mercury

Other Words from mercurial


mercurially \ (ˌ)mər-​ˈkyu̇r-​ē-​ə-​lē How to pronounce mercurial (audio) \ adverb
mercurialness noun

Choose the Right Synonym for mercurial


inconstant, fickle, capricious, mercurial, unstable mean lacking firmness or steadiness (as in purpose or devotion). inconstant implies an incapacity for steadiness and an inherent tendency to change. an inconstant friend fickle suggests unreliability because of perverse changeability and incapacity for steadfastness. performers discover how fickle fans can be capricious suggests motivation by sudden whim or fancy and stresses unpredictability. an utterly capricious critic mercurial implies a rapid changeability in mood. made anxious by her boss's mercurial temperament 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

Did you know?

The Roman god Mercury was the messenger and herald of the gods and also the god of merchants and thieves (his counterpart in Greek mythology is Hermes). He was noted for his eloquence, swiftness, and cunning, and the Romans named what appeared to them to be the fastest-moving planet in his honor. Mercurial comes from the Latin adjective mercurialis, meaning "of or relating to Mercury."

Examples of mercurial in a Sentence

Adjective Few moments in English history have been more hungry for the future, its mercurial possibilities and its hope of richness, than the spring of 1603. — Adam Nicolson, God's Secretaries, 2003 Though you could see all three places in one day, each of them makes you want to stay or to keep returning to watch the effects of the changing weather and the mercurial Sicilian light. — Francine Prose, Atlantic, December 2002 Some scientists suggest that because manic-depressive patients are ever riding the bio-chemical express between emotional extremes, their brains end up more complexly wired and remain more persistently plastic than do the brains of less mercurial sorts. — Natalie Angier, New York Times, 12 Oct. 1993 Still grinning, still miming, he samba-ed across the floor … and started in on the dishes with a vigor that would have prostrated his mercurial cousin. — T. Coraghessan Boyle, Harper's, October 1987 the boss's mood is so mercurial that we never know how he's going to react to anything
Recent Examples on the Web: Adjective Comedians are notorious for being mercurial, thriving on public adulation. Malina Saval, Variety, 22 July 2022 Nadal will next face mercurial Australian star Nick Kyrgios in the semis on Friday after Kyrgios prevailed in straight sets over Cristian Garin of Chile. Adam Zagoria, Forbes, 6 July 2022 Democrats are also very wary of scaring off the mercurial Manchin with any pressure, despite knowing that a major economic package could potentially boost their political chances significantly. Trish Turner, ABC News, 6 July 2022 If there’s no room for Dave Mastio — decent, measured, judicious, professional — there sure as hell is no room for mouthy, mercurial me. Jay Nordlinger, National Review, 29 June 2022 There was a darn good reason Kyrie Irving opted into the final year of his contract with the Brooklyn Nets instead of testing free agency: there was no interest in a team with salary cap space that wanted to invest long term in the mercurial guard. Globe Staff,, 29 June 2022 Christie’s lone season as a Spartan was a mercurial one. Chris Solari, Detroit Free Press, 24 June 2022 If one starts to slide -- similar to 2019, when the Cavs jumped back into the first round for mercurial Kevin Porter Jr. -- the Cavs could have enough trade capital to make a deal. Chris Fedor, cleveland, 23 June 2022 He's never been identified as anything other than this mercurial or puppeteer-like, quasi-evil, greedy manager that took advantage of Elvis from the get-go. Maureen Lee Lenker,, 23 June 2022 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'mercurial.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of mercurial


14th century, in the meaning defined at sense 1


1676, in the meaning defined above

History and Etymology for mercurial


see mercury


see mercury

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Last Updated

4 Aug 2022

Cite this Entry

“Mercurial.” Dictionary, Merriam-Webster, Accessed 18 Aug. 2022.

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More Definitions for mercurial


mer·​cu·​ri·​al | \ (ˌ)mər-ˈkyu̇r-ē-əl How to pronounce mercurial (audio) \

Medical Definition of mercurial

 (Entry 1 of 2)

: of, relating to, containing, or caused by mercury mercurial salves



Medical Definition of mercurial (Entry 2 of 2)

: a pharmaceutical or chemical containing mercury the diuretic action of mercurials

More from Merriam-Webster on mercurial

Nglish: Translation of mercurial for Spanish Speakers


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