whippersnapper
noun /ˈwɪpəsnæpə(r)/
/ˈwɪpərsnæpər/
(old-fashioned, informal)- a young and unimportant person who behaves in a way that others think is too confident and rude
狂妄小子 词源late 17th cent.: perhaps representing whipsnapper, expressing noise and unimportance.