smart-ass 自作聪明的；自以为了不起的家伙；自以为是的

【例句】
He despaired later that people seemed to like him as "the cocky hero and the smart-ass and the rake" .
他绝望地发现自己所扮演的高傲的英雄，自作聪明的人物，以及浪子的形象反倒颇受人们的欢迎。

The Smart-Ass exposes your intellectual weaknesses and will subsequently cut you down because of it.
这种自以为是的人会让你暴露出智力上的弱点，随后因此伤害你的感情。