mercurial

Meanings

Noun

• Any of the plants known as mercury, especially the annual mercury or French mercury (Mercurialis annua).
• A person born under the influence of the planet Mercury; hence, a person having an animated, lively, quick-witted or volatile character.
• A chemical compound containing mercury.
• A preparation of mercury, especially as a treatment for syphilis.

Adjective

• Having a lively or volatile character; animated, changeable, quick-witted.
• Pertaining to the astrological influence of the planet Mercury; having the characteristics of a person under such influence (see adjective sense 1).
• Pertaining to the planet Mercury.
• Of or pertaining to the element mercury or quicksilver; containing mercury.
• Caused by the action of mercury or a mercury compound.
• Pertaining to Mercury, the Roman god of, among other things, commerce, financial gain, communication, and thieves and trickery; hence , money-making; crafty.

Origin

• Noun sense 1 (“(obsolete) plant known as mercury”) is from Middle English mercurial, mercuryal, from Anglo-Norman mercurial and Old French mercurial, or directly from their etymon Latin mercuriālis, from mercuriālis, from Mercurius + -ālis.
• Later adjective and noun uses may have been directly derived from Latin mercuriālis,