The verb deride means to show a low opinion of someone or something. The jerk would deride the other kids on the bus by calling them names or pulling their hair until the driver decided to de-ride him by kicking him off the bus.
To "ride" people is to get on their case or give them a hard time, and to deride is to do the same with insulting language or poor treatment. Deride comes from the Latin root dērīdēre, meaning "to ridicule, to scorn," and it's often used to express dislike or even hatred. Criticizing something with words is a common way to deride, and politicians often deride each other in their speeches during election campaigns.