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.