C1 adjective /ˈfɪk.əl/
Fickle
気まぐれな; 不安定な; 変わりやすい;
Meaning
changeable; inconstant; liable to sudden unpredictable change
Example
His fickle nature made it hard to trust his promises.
彼の気まぐれな性格は、彼の約束を信じることを難しくした。