mercurial
Americanadjective
-
changeable; volatile; fickle; flighty; erratic.
a mercurial nature.
- Synonyms:
- indecisive, inconstant
-
animated; lively; sprightly; quick-witted.
- Synonyms:
- spirited
- Antonyms:
- phlegmatic
-
pertaining to, containing, or caused by the metal mercury.
-
(initial capital letter) of or relating to the god Mercury.
-
(initial capital letter) of or relating to the planet Mercury.
noun
adjective
-
of, like, containing, or relating to mercury
-
volatile; lively
a mercurial temperament
-
(sometimes capital) of, like, or relating to the god or the planet Mercury
noun
Other Word Forms
Etymology
Origin of mercurial
First recorded in 1350–1400; Middle English, from Latin mercuriālis “of or pertaining to the god or planet Mercury”; see origin at mercury, -al 1
Explanation
Mercurial describes someone whose mood or behavior is changeable and unpredictable, or someone who is clever, lively, and quick. With a mercurial teacher, you never know where you stand. Mercury was the ancient Roman god of commerce and messenger of the gods, and the planet Mercury was named after the Roman god. In Middle English, this adjective meant "relating to the planet or god Mercury" and derives from Latin mercuriālis, from Mercurius "Mercury." A mercurial personality has the unpredictability associated with the god Mercury or, in astrology, is supposedly influenced by the planet.
Vocabulary lists containing mercurial
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Soprano Lise Davidsen was a mercurial Lady Macbeth, pushing her husband into dark deeds yet with more sides to her than her steely, ringing high notes would suggest.
From The Wall Street Journal ● Sep. 24, 2026
Stubb said the mercurial US leader had "been very good for NATO," despite his frequent criticism of the military alliance.
From Barron's ● Sep. 15, 2026
Cherki made his impact under Guardiola last season, although there was always a feeling the mercurial signing from Lyon for a bargain £30m could produce more.
From BBC ● Aug. 28, 2026
BTS has a mercurial relationship with the Grammys, having been nominated five times in various categories since becoming the first K-pop group nominated in 2019, and performing for the live telecast.
From Los Angeles Times ● Jul. 29, 2026
In Lagos, the harmattan was a mere veil of haze, but in Nsukka, it was a raging, mercurial presence; the mornings were crisp, the afternoons ashen with heat, and the nights unknown.
From "Americanah" by Chimamanda Ngozi Adichie
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Get a wordDefinitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
