Acting like you are better than the people around you. A supercilious person does not usually shout or insult anyone — that is the point of the word. They are cool and polite on the surface, and the message comes through anyway: a small smile, a slow look up and down, a reply that is one word shorter than it should be. You feel talked down to, but there is nothing you can point at and complain about. It describes people, and also faces, voices, smiles, and manners: a supercilious smile, a supercilious tone. It is a strong word of disapproval — you would not use it about yourself, and you would not say it to someone's face. It is also a fairly formal, bookish word. In Taiwan you will meet it in reading and in exam vocabulary lists far more often than in conversation; native speakers in daily speech are more likely to say 'stuck-up', 'snobby', or 'looks down on people'. It usually points at how someone behaves toward others, so it is a little different from 'proud' (which can be good) or 'arrogant' (which is louder and can be about believing you are great at something, with nobody else in the picture).

傲慢的、目中無人的、瞧不起人的（帶輕蔑的那種高傲，通常表現在表情和語氣上，不是大聲吵鬧；口語常說「很跩」「很臭屁」，但這個字本身是書面語）