Mer*cu"ri*al (?), a. [L. mercurialis, fr. Mercurius Mercury: cf. F. mercuriel.]
1.
Having the qualities fabled to belong to the god Mercury; swift; active; sprightly; fickle; volatile; changeable; as, a mercurial youth; a mercurial temperament.
A mercurial man
Who fluttered over all things like a fan.
Byron.
2.
Having the form or image of Mercury; -- applied to ancient guideposts.
[Obs.]
Chillingworth.
3.
Of or pertaining to Mercury as the god of trade; hence, money-making; crafty.
The mercurial wand of commerce.
J. Q. Adams.
4.
Of or pertaining to, or containing, mercury; as, mercurial preparations, barometer. See Mercury, 2.
5. Med.
Caused by the use of mercury; as, mercurial sore mouth.
© Webster 1913.
Mer*cu"ri*al, n.
1.
A person having mercurial qualities.
Bacon.
2. Med.
A preparation containing mercury.
© Webster 1913.