fickle; capricious; changeable
Describes a person or their feelings that shift easily; often used for romantic interest or hobbies. The noun form can refer to such a personality trait.
He is fickle and quickly gets absorbed in another hobby.
Because of my capricious nature, I can't stick with anything for long.
移り気 stresses the act of one's interests or affections shifting from one thing to another, whereas 浮気 often carries a lighter, more frivolous connotation of inconstancy.
移り気 emphasizes a changeable, fickle mind that shifts affection or interest, while 飽きっぽい specifically stresses getting bored with things quickly.
移り気 specifically describes fickle affections or interests, often in romance, whereas 気まぐれ can describe any sudden, unpredictable whim.
Compound of 移り (continuative form of 移る 'to move, shift') + 気 ('spirit, mind'). The combination conveys a mind that shifts easily.