mercurial

adjective
mer·​cu·​ri·​al | \(ˌ)mər-ˈkyu̇r-ē-əl \

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

mercurial

noun
mer·​cu·​ri·​al | \(ˌ)mər-ˈkyu̇r-ē-əl \

Definition of mercurial (Entry 2 of 2)

: a pharmaceutical or chemical containing mercury

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Other Words from mercurial

Adjective

mercurially \-​ē-​ə-​lē \ adverb
mercurialness noun

Choose the Right Synonym for mercurial

Adjective

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?

Adjective

The Roman god Mercury ("Mercurius" in Latin) 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. The Latin adjective derived from his name, mercurialis, meaning "of or relating to Mercury," was borrowed into English in the 14th century as "mercurial." Although the adjective initially meant "born under the planet Mercury," it came to mean also "having qualities of eloquence, ingenuity, or thievishness attributed to the god Mercury or the influence of the planet Mercury," and then "unpredictably changeable."

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
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Recent Examples on the Web: Adjective

Musk’s apparent decision to back out of the SEC deal is yet another example of the executive’s mercurial personality undermining his larger business interests and goals. Emily Stewart, Vox, "Elon Musk reportedly almost avoided a federal lawsuit — but then backed out," 29 Sep. 2018 Still, Trump is known as a mercurial boss, whose feelings on key staffers can shift rapidly. Zeke Miller, The Seattle Times, "Trump chief of staff says he will stay at Trump’s request," 31 July 2018 In Oval Office meetings, Sanders quietly observed how Hicks picked her battles with their mercurial boss -- and took notes -- two sources familiar told CNN. Jeff Zeleny, CNN, "Sanders' challenge: Maintaining credibility, while staying loyal to Trump," 7 June 2018 CalcioMercato are reporting that the Italian club are looking to tie Sarri down in the long term to avoid losing their mercurial boss. SI.com, "Report: Maurizio Sarri Set for Showdown Talks With Napoli," 12 May 2018 The document prepared by the committee’s Democratic staff paints a picture of a medical office that was casual with the prescribing and distribution of drugs but terrorized by a mercurial boss, quick to temper. Nicholas Fandos, BostonGlobe.com, "Jackson is said to have recklessly prescribed drugs, crashed government vehicle while drunk," 25 Apr. 2018 So far, their mercurial boss hasn’t done or tweeted anything outrageous. Bill Powell, Newsweek, "Despite Trump Tweet Storm, Mattis and McMaster Calling Shots in Iran Crisis," 9 Jan. 2018 Computers are mercurial, but Microsoft strapped an operating system on top of them—first with DOS, then with Windows—and commoditized that processing power. Bloomberg.com, "GitHub Is Microsoft’s $7.5 Billion Undo Button," 6 June 2018 These were strong words from the telegenic, soft-spoken leader, who has spent the two-day summit trying to strike a precarious balance between being Canada’s protector-in-chief but not inciting the mercurial American president. Dan Bilefsky, New York Times, "Trump’s ‘Bully’ Attack on Trudeau Outrages Canadians," 10 June 2018

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.

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First Known Use of mercurial

Adjective

14th century, in the meaning defined at sense 1

Noun

1676, in the meaning defined above

History and Etymology for mercurial

Adjective

see mercury

Noun

see mercury

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Statistics for mercurial

Last Updated

14 Dec 2018

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Time Traveler for mercurial

The first known use of mercurial was in the 14th century

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More Definitions for mercurial

mercurial

adjective

English Language Learners Definition of mercurial

: changing moods quickly and often

: changing often : very changeable

: very lively and quick

mercurial

adjective
mer·​cu·​ri·​al | \(ˌ)mər-ˈkyu̇r-ē-əl \

Medical Definition of mercurial 

(Entry 1 of 2)

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

mercurial

noun

Medical Definition of mercurial (Entry 2 of 2)

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

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More from Merriam-Webster on mercurial

Rhyming Dictionary: Words that rhyme with mercurial

Thesaurus: All synonyms and antonyms for mercurial

Spanish Central: Translation of mercurial

Nglish: Translation of mercurial for Spanish Speakers

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