不可一世
As proud(vain) as a peacock.
Puffed up with pride.
As proud as Lucifer.
eg：When John learned that he had got the scholarship, he was as proud as a peacock.
同义词：趾高气扬 Have one's nose in the air.
反义词：无颜面对江东父老 To fly from the face of men.
