自以为是的人;妄自尊大的人 If you refer to a young person as a whippersnapper, you disapprove of them because you think that they are behaving more confidently than they should.
【语用信息】:disapproval
【语域标签】:INFORMAL 非正式
【STYLE标签】:OLD-FASHIONED 过时
...this bunch of irresponsible young whippersnappers.
这群不负责任自以为是的年轻人
Noun
1. someone who is unimportant but cheeky and presumptuous