如果你形容一个人smug，那么就是说这个人是对自己非常满意的。他经常会得意的笑或者说话时非常自以为是，挺着胸脯走路并且以自我为中心。Smug是modest(谦虚的)和unsure(不确定的)的反义词。

too pleased or satisfied about something you have achieved or something you know

沾沾自喜的，自鸣得意的

There was a hint of smug self-satisfaction in her voice.

她的言语中流露出一丝自鸣得意。

He's been unbearably smug since he gave up smoking.

他戒烟之后，那个得意劲儿简直让人难以忍受。