mercurial

[Klimt]

[mer-kyoor-ee-uhl]

1. changeable; volatile; fickle; flighty; erratic: a mercurial nature.
2. animated; lively; sprightly; quick-witted.

He was not a mercurial man, who easily changed his point of view.

She has her own occupations to attend to; and besides, she is too old to run after a child, and he is too mercurial to be tied to an elderly woman.

[Slava]

Other definitions of mercurial:

Berlusconi of Italy.
North Korea.

[LukeJavan8]

Iran.