look down on (someone or something)
To regard oneself as superior to someone or something and thus act in a haughty or snobbish manner. The well-dressed businessman looked down on the kid wearing a T-shirt in the elevator, not knowing that he was the new CEO. I have no idea why some people look down on those who speak with an accent—that means they know at least two languages!
look down on
Also, look down one's nose at. Regard with contempt or condescension, consider oneself superior to. For example, When it comes to baking, Beth is a purist-she looks down on anyone who uses a mix, or Seniors have a way of looking down their noses at juniors. The first expression dates from about 1700, the second from about 1900.