Definition
Behaving in a superior, arrogant, and disdainful manner, as if one is much more important than others.
自覺了不起
Ever since his promotion, he has become high and mighty, looking down on us old colleagues.
自從升職後，他就變得目中無人，瞧不起我們這些老同事。
She always acts high and mighty, as if she were the boss around here.
她總是表現得高高在上，好像她是這裡的老闆。
Don't be so high and mighty, we are all equals.
別這麼目中無人，我們都是平等的。