If you describe someone as fickle, you disapprove of them because they keep changing their mind about what they like or want.
The group has been notoriously fickle in the past.
这个团体在过去是出了名的善变。
If you say that something is fickle, you mean that it often changes and is unreliable.
New England's weather can be fickle.
新英格兰的天气变幻莫测。