n.自以为无所不知的人，自以为是的人

Don't listen to him, he's just being a wiseacre trying to impress everyone with his so-called knowledge.
别听他的，他只是在装聪明，想用他所谓的知识给大家留下印象。
My little sister has turned into quite the wiseacre since she started college; she thinks she knows everything now.
自从我妹妹上了大学，她变得特别爱卖弄小聪明，觉得自己现在什么都知道了。
Whenever there's a discussion, Tom always jumps in with some wiseacre comment that he thinks is hilarious but nobody else does.
每当有讨论时，汤姆总是会插进一些他自认为很幽默但实际上没人觉得好笑的俏皮话。
The new intern tried to act like a wiseacre during the meeting, but his lack of experience showed when he couldn't back up his claims with facts.
新来的实习生在会议中试图表现得很机灵，但当他无法用事实支持自己的主张时，他的经验不足就暴露出来了。
She rolled her eyes at the wiseacre's attempt to correct the professor in front of the whole class.
她对那个在全班同学面前试图纠正教授的自作聪明者翻了个白眼。
I used to be such a wiseacre in school, always having a smart remark ready, but it didn't win me many friends.
我以前在学校里总爱卖弄小聪明，随时准备发表机智的评论，但这并没有让我交到很多朋友。
The wiseacre thought he could outsmart the detective, but his clever tricks only led him closer to getting caught.
那个自作聪明的人以为他能比侦探更聪明，但他的那些小聪明只会让他更快被逮住。
He's not really being helpful; he's just being a wiseacre and making snarky comments from the sidelines.
他其实并不是在帮忙，他只是在旁边卖弄聪明，发表讽刺的评论。
The wiseacre's constant interruptions with unnecessary trivia made the lecture unbearable for everyone.
那个爱炫耀自己博学的人不断地打断演讲，插入不必要的琐事，让所有人都难以忍受。
Instead of admitting she didn't understand, she tried to cover it up with a wiseacre remark that only confused things further.
她没有承认自己不懂，而是试图用一句故作聪明的评论来掩饰，结果反而让事情更加混乱。