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
- mercuriality noun
- mercurially adverb
- mercurialness noun
- unmercurial adjective
- unmercurially adverb
- unmercurialness noun
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.
Chelsea's Cole Palmer showed his quality with a goal in the Euro 2024 final in Berlin and has the sort of mercurial talent that could give England an X-factor in the World Cup.
From BBC • Apr. 1, 2026
As Simon Elliott describes in his biography “The African Emperor,” Severus was a mercurial and contradictory character, capable by turns of savagery, cunning, wit and generosity, and always blessed with a sense of the theatrical.
From The Wall Street Journal • Mar. 19, 2026
As Cassio, both Jake Roxander and Andrew Robare were notably cocky and mercurial.
From The Wall Street Journal • Mar. 18, 2026
In recent years, the mercurial superstar has faced a number of public and legal dramas.
From Los Angeles Times • Mar. 11, 2026
He was in a mercurial Hastings temper, and a halter and chain looped over his bridle barely restrained him.
From "Seabiscuit: An American Legend" by Laura Hillenbrand
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.
