fickle 墙头草,两边倒

•  adjective

1    someone who is fickle often changes their opinion about what they want or like:
?Every politician knows that voters are fickle.
* fickle weather, fortune 变化无常的天气、 变幻莫测的命运
2    something that is fickle, such as the weather, often changes suddenly
* a fickle person, lover, etc, ie not faithfulor loyal 出尔反尔的人、