mercurial
Concise Oxford English Dictionary © 2008 Oxford University Press:
mercurial /məːˈkjʊərɪəl/
▶adjective
- 1 subject to sudden changes of mood or mind.
- 2 of or containing the element mercury.
- 3 (Mercurial) of the planet Mercury.
– derivatives
mercuriality /-ˈalɪti/ noun,
mercurially adverb.
mercuriality /-ˈalɪti/ noun,
mercurially adverb.
– origin ME: from L. mercurialis ‘relating to the god Mercury’, from Mercurius ‘Mercury’.
'mercurial' also found in these Oxford entries:

