1

mercurial

adjective mer·cu·ri·al \ (ˌ)mər-ˈkyu̇r-ē-əl \
Updated on: 9 Dec 2017

Definition of mercurial

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

play \-ē-ə-lē\ adverb

mercurialness

noun

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Examples of mercurial in a Sentence

  1. 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 NicolsonGod's Secretaries2003
  2. 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 ProseAtlanticDecember 2002
  3. 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 AngierNew York Times12 Oct. 1993
  4. 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 BoyleHarper'sOctober 1987
  5. the boss's mood is so mercurial that we never know how he's going to react to anything

Recent Examples of mercurial from the Web

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.

Did You Know?

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."

Origin and Etymology of mercurial

Synonym Discussion of 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

2

mercurial

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

Definition of mercurial

: a pharmaceutical or chemical containing mercury

Origin and Etymology of mercurial

Other Chemical Engineering Terms


MERCURIAL Defined for English Language Learners

mercurial

adjective

Definition of mercurial for English Language Learners

  • : changing moods quickly and often

  • : changing often : very changeable

  • : very lively and quick


Medical Dictionary

1

mercurial

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

medical Definition of mercurial

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

2

mercurial

noun

medical Definition of mercurial

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


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