Chip on his Shoulder
指某人因过去的不快而心怀怨恨，容易动怒或挑衅。
形容人因旧怨而态度敌对。
英文释义
Angry today about something that occured in the past.
例句
He still has a chip on his shoulder about losing the championship last year.
典故来源
源于19世纪美国，男孩将木屑放在肩上挑衅他人，若被撞掉则引发争斗。