Demonstration

Noun

1. The act of demonstrating; showing or explaining something. A prisoner's act of beating up another prisoner. (clarification of this definition is needed.)
2. A prisoner's act of beating up another prisoner. (clarification of this definition is needed.)
3. An event at which something will be demonstrated.

   "I have to give a demonstration to the class tomorrow, and I'm ill-prepared."

4. Expression of one's feelings by outward signs.
5. A public display of group opinion, such as a protest march.