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
Derived 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.
Mercurial and unreliable in the studio, Stewart would sometimes fall asleep on the couch during recording sessions or lie down in the vocal booth.
From The Wall Street Journal • Mar. 27, 2026
Mercurial boxer Ryan Garcia caught a break Tuesday when a judge dismissed a misdemeanor vandalism charge against him over the objections of the Los Angeles County district attorney’s office.
From Los Angeles Times • Oct. 9, 2024
Mercurial running back Najee Harris has struggles at times to put into words his frustration with the direction of the offense following losses.
From Seattle Times • Nov. 29, 2023
Still, the decline was smaller than expected, according to analysts, thanks also to higher-priced product launches such as the LeBron 20s and Nike Mercurial shoes.
From Reuters • Dec. 21, 2022
Mercurial medicines, diuretics of different kinds, and bitters, had been trying for the last three months, but with little advantage.
From An Account of the Foxglove and some of its Medical Uses With Practical Remarks on Dropsy and Other Diseases by Withering, William
Definitions 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.
