# mercurial

Pronunciation: say "mur-KYUUR-ee-uhl" US /mɝˈkjʊ.ɹi.əl/, UK /məːˈkjʊə.ɹɪ.əl/

## Adjective

1. Changing suddenly and unpredictably in mood or behavior; also, lively and quick-witted.
   - Simple: Often changing moods suddenly and without warning, or full of energy and quick to think.
   - _Her mercurial temperament made her a thrilling performer and a difficult colleague._
   - _The team's mercurial striker can win a match on his own or disappear for weeks._
2. Relating to, containing, or caused by the element mercury.
   - Simple: Containing mercury, the liquid silver metal, or having to do with it.
   - _Many hospitals have replaced mercurial thermometers with digital ones._
   - _Workers in the old mine breathed mercurial vapors for years without protection._
3. Relating to the astrological influence of the planet Mercury, or having the traits of a person born under that influence.
   - Simple: In astrology, having to do with the planet Mercury's effect on people, or having the nature it is said to give.
   - _Her astrologer insists that the child's chart shows a mercurial nature, drawn to books and learning._
   - _The almanac warned that the week's mercurial influences would bring confusing letters and news._
4. Relating to Mercury, the Roman god of commerce, gain, communication, and thieves, among other things; by extension, money-making or crafty.
   - Simple: Having to do with Mercury, the Roman god of trade, messages, and thieves. Also, sly or good at making money.

## Other meanings

- (adjective) Relating to the planet Mercury.
- (noun) A person born under the influence of the planet Mercury, or, by extension, someone eloquent, quick-witted, furtive, or volatile in character.
- (noun) A chemical compound containing mercury, including drugs of this kind once used to treat syphilis.
- (noun) Any of the plants called mercury, especially annual mercury, also known as French mercury (Mercurialis annua).

## Origin

From Latin mercuriālis, 'of Mercury', from Mercurius, the Roman god. The changeable sense comes from the old astrological belief that people born under the planet Mercury were quick and volatile.

Source: DictionaryAI, https://dictionaryai.com/define/mercurial (written from Wiktionary data, CC BY-SA 4.0: https://creativecommons.org/licenses/by-sa/4.0/).