Mercurial

Literarypsychologyself

Etymology

From the Roman god Mercury, fleet messenger of the gods, and the planet and metal named for him. Quicksilver (mercury) scatters at a touch, and medieval astrology held that those born under Mercury were changeable and quick. The personality sense pooled from both.

  1. adjective · /mur-KYOOR-ee-ul/

    Liable to sudden, unpredictable changes of mood or mind.

    What it names

    The temperament that keeps everyone slightly off balance — quick, volatile, hard to forecast.

    Example

    Her mercurial boss praised the plan on Monday and killed it on Tuesday.

    Related idea

    Capricious stresses whim; mercurial stresses the speed and unpredictability of the shift.

See also

ArbitraryCapriciousProteanSaturnine