Other forms: cavaliers
Someone who is cavalier has a dismissive attitude and regards other people as inferior. If you think you know more than your teacher and never bother doing homework, your parents might complain that you are cavalier about your studies.
The word cavalier dates from mid-16th-century French, from the Latin caballus, meaning “horse.” If you have a cavalier attitude, you look down on other people — as if you are sitting on a very tall horse and other people are sitting down there on the ground.