Meaning
Lively, quick-witted, and quick to change - a temperament that shifts like the god's own sandals between brilliance, charm, and sudden reversal. Applied to people it is half compliment, half warning; applied to prices and weather it just means volatile. The compliment is real but the volatility is the point; in science it means only containing mercury, which can surprise readers meeting it in old pharmacology. Regional use: General English; Roman origin.
Origin
Mercury was the Roman god of commerce, travellers, eloquence, luck, and trickery, guide of souls to the underworld, wing-shoed and boundary-hopping - inherently elusive, constantly in motion. The word's path into English runs through the god's herb: Middle English mercurial came via Old French from Latin mercurialis, short for herba mercurialis, the plant of Mercury, and the senses multiplied from the fifteenth century - pertaining to the god by 1400s, the planet, the element quicksilver whose restless behaviour earned the god's name, the mercurial thermometer, and by the seventeenth century the temperament. Bacon described a youth in 1622 as such a Mercuriall as the like hath seldom beene knowne; Shakespeare's Cymbeline gives a foot Mercuriall; and the modern obituary sense was already in place when the Guardian called Robert Maxwell one of the most mercurial postwar operators in 1991.
Research Sources
References used to check this entry’s meaning, history, or documented forms.
Variants
- a mercurial temperament
- mercurial wit
- mercurially
Usage Examples
- The chairman was mercurial to a fault: visionary at breakfast, litigious by lunch, serene again at dinner.
- Her mercurial wit made the Tuesday seminar unmissable and the final exam wholly unpredictable.
- Copper prices stayed mercurial all quarter, which the traders blamed, etymologically, on the god.