mercurial

[mer-kyoor-ee-uhl] / mərˈkyʊər i əl /

ADJECTIVE

flighty, temperamental

Synonyms

STRONGEST

changeable effervescent erratic impulsive resilient unpredictable volatile

WEAK

blowing hot and cold bubbleheaded buoyant capricious elastic expansive fickle flaky flip fluctuating gaga gay inconstant irregular irrepressible lighthearted lively lubricious mad mobile movable quicksilver spirited sprightly ticklish unstable up-and-down variable yo-yo

Antonyms

STRONGEST

certain constant predictable reliable stable steady sure unchanging

WEAK

calm tranquil unchangeable unperturbable unvarying

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.

Isolde is a mercurial character, and Ms. Davidsen expressed her simmering rage, her girlish flirtatiousness, and her serenity in the “Liebestod.”

From The Wall Street Journal • Mar. 11, 2026

In recent years, the mercurial superstar has faced a number of public and legal dramas.

From Los Angeles Times • Mar. 11, 2026

Still, China is treading carefully because one of the biggest calculations for them is the mercurial US president, who is due to arrive for a much-awaited meeting later this month.

From BBC • Mar. 5, 2026

While they have lost mercurial full-back Ange Capuozzo to injury, centre Ignacio Brex has returned to the set-up after missing the past two games for personal reasons.

From BBC • Mar. 3, 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

Vocabulary lists containing mercurial

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