Adjective: mercurial mur'kyûr-ee-ul
- Liable to sudden unpredictable change
"mercurial twists of temperament";
- erratic, fickle, quicksilver
- Relating to, containing or caused by mercury
"mercurial preparations"; "mercurial sore mouth"
- Relating to or having characteristics (eloquence, shrewdness, swiftness, thievishness) attributed to the god Mercury
"more than Mercurial thievishness"
- Relating to or under the (astrological) influence of the planet Mercury
"the Mercurial canals"
See also: changeable, changeful
Encyclopedia: Mercurial