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.
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.
5. (Science: medicine) Caused by the use of mercury; as, mercurial sore mouth.
Origin: L. Mercurialis, fr. Mercurius Mercury: cf. F. Mercuriel.
1. A person having mercurial qualities.
2. (Science: medicine) A preparation containing mercury.