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.

There’s an informality built into the production, but it’s somewhat deceptive because the mercurial staging is extremely precise.

From Los Angeles Times • Jun. 12, 2026

Your first chance to see whether mercurial French forward Kylian Mbappé, the world’s best player, is paying full attention this year.

From Salon • Jun. 11, 2026

The trial also showed Musk’s volcanic temper and mercurial side.

From The Wall Street Journal • May 16, 2026

President Donald Trump has a notably mercurial personality.

From BBC • Apr. 28, 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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