The term 'Classroom Missile' refers to a type of mischievous behavior that involves the use of objects such as spitballs, peas, and erasers. Spitballs are small balls of paper or other material that are often thrown in classrooms, while peas are small round objects that can be thrown for similar purposes. Erasers are used to erase pencil marks, but can also be thrown as projectiles. All three items can be used to cause disruption in a classroom setting.