• Today's Word

Mercurial

🔊 Listen to the word Mercurial

mur-KYOOR-ee-uhl

Definition

(adjective) Subject to sudden or unpredictable changes of mood or mind.

Example

Her mercurial temperament made collaboration both exciting and exhausting.

Word Origin

Mid 17th century: from Latin mercurialis ‘relating to the god Mercury’, known for his speed and unpredictability.

Fun Fact

Mercurial originally referred to qualities associated with Mercury, the Roman messenger god—quick, clever, and elusive. Today, the word is often used to describe emotionally volatile people, though it can also apply to markets, creative energy, or political behavior. In psychology, a mercurial personality isn’t just moody—it’s brilliant, erratic, and hard to pin down.