1. To appear in a show, on T.V., radio, etc.; SYN. be on.
2. To grow late or (of time) elapse.
3. When you move your body toward something and stand, sit, or lie on it, you get on it.
4. When you mount an animal, bicycle, motorcycle, and so on, you get on it.
5. When you enter a bus, train, airplane, ship, and so on, you get on it.