mercurial
1 of 2adjective
mer·cu·ri·al (ˌ)mər-ˈkyu̇r-ē-əl 
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
mercurially
(ˌ)mər-ˈkyu̇r-ē-ə-lē
adverb mercurialness noun
mercurial
2 of 2noun
: a pharmaceutical or chemical containing mercury
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."
Synonyms
Adjective
- capricious
- changeable
- changeful
- fickle
- flickery
- fluctuating
- fluid
- inconsistent
- inconstant
- mutable
- skittish
- temperamental
- uncertain
- unpredictable
- unsettled
- unstable
- unsteady
- variable
- volatile
See all Synonyms & Antonyms 
Example Sentences
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
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 Shawn Tully, Fortune, 3 Aug. 2022 Those older guys include mercurial, yet capable quarterback Dorian Thompson-Robinson. Josh Newman, The Salt Lake Tribune, 24 Aug. 2022 When House of the Dragon producers first began to contemplate casting an actor to play the pivotal role of Daemon Targaryen — a mercurial and enigmatic prince — one name kept popping up. James Hibberd, The Hollywood Reporter, 23 Aug. 2022 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, BostonGlobe.com, 29 June 2022 See More
Adjective
Saylor’s emotional, mercurial style ignites heavy churn in the c-suite, hindering MicroStrategy’s growth. Shawn Tully, Fortune, 3 Aug. 2022 Those older guys include mercurial, yet capable quarterback Dorian Thompson-Robinson. Josh Newman, The Salt Lake Tribune, 24 Aug. 2022 When House of the Dragon producers first began to contemplate casting an actor to play the pivotal role of Daemon Targaryen — a mercurial and enigmatic prince — one name kept popping up. James Hibberd, The Hollywood Reporter, 23 Aug. 2022 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, BostonGlobe.com, 29 June 2022 See More Word History
Etymology
Adjective
see mercury
Noun
see mercury
First Known Use
Adjective
14th century, in the meaning defined at sense 1
Noun
1676, in the meaning defined above
Medical Definition
mercurial 1 of 2
adjective
mer·cu·ri·al (ˌ)mər-ˈkyu̇r-ē-əl
: of, relating to, containing, or caused by mercury
mercurial salves
mercurial
2 of 2noun
: a pharmaceutical or chemical containing mercury
the diuretic action of mercurials
mercurialness
noun
as in whimsicalness
Synonyms & Similar Words
Relevance
- whimsicalness
- unpredictability
- capriciousness
- whimsicality
- impulsiveness
- volatileness
- freakishness
- eccentricity
- flakiness
- volatility
- arbitrariness
- moodiness
- fickleness
- willfulness
- changeability
- mutability
- caprice
- variableness
- variability
- irregularity
- flexibility
- inconstancy
Antonyms & Near Antonyms
- practicality
- reasonableness
- immutability
- reasonability
- levelheadedness
- firmness
- invariability
- inflexibility
- stability
- immovableness
- fixedness
- fastness
- immovability
- steadfastness
- steadiness
- constancy
- changelessness