chip做动词解释的时候，意思有“打缺，弄缺；铲，凿，削”，而chip on one's shoulder的本意是指“容易发怒的，好斗的情绪，怀恨在心”等意思。

【例句】
In interviews after the game, the American team showed how to be graceful in defeat. Team members didn't seem to have a chip on their shoulders.
在赛后接受采访时，美国队显示了如何从容地面对失利。她们一点也没有怀恨在心。

Every time I try to talk to you, you've got a chip on your shoulder.
每次我跟你说话的时候，你都好像对我怀恨在心似的。