an axe to grind
别有目的地做某事，通常是出于个人利益或私人动机
口语·形容怀有私心或不满
英文释义
to have a hidden personal agenda or ulterior motive
例句
He has an axe to grind with the manager ever since he was passed over for promotion.
典故来源
源自19世纪美国，原指磨斧头时带有个人目的，后引申为隐藏的私怨或动机。