[adjective] [disapproving] - likely to change your opinion or your feelings suddenly and without a good reasonShe's so fickle - she's never been interested in the same man for more than a week!The world of popular music is notoriously fickle.(disapproving) The weather is described as fickle if it tends to change suddenly and without warning.Fickle winds made sailing conditions difficult.
FICKLE
Meaning of FICKLE in English
Cambridge English vocab. Кембриджский английский словарь. 2012