Changeable, changeful, inconstant, uncertain, unreliable. of persons, their attributes, feelings, etc.; also often, with personification, of…

Inconstant in mind, will, or disposition; fickle; variable. Now chiefly literary and poetic.

That moves constantly, shifting, unstable, wandering; hence of a person or his attributes: Changeable, fickle, inconstant, vacillating. Obsolete.

Of a person or a personal attribute or opinion: changeable, shifting, inconstant. Obsolete.

Deprived of a bottom or foundation; unsettled.

Variable, changeable. Obsolete.

Of a person's mind, imagination, temperament, etc.: likely to change or display different aspects; shifting; versatile; (also) lacking focus…