The definition of a mad person is a person who is or behaves as if insane; lunatic; maniac.
When you say that someone is mad, you mean that they are very angry.
You're just mad at me because I don't want to go.
The definition of mad is defined as angry, insane, foolish, frantic or extremely funny.
An example of mad is child who is not able to do what he wants to do.
An example of mad is a psychopath.
An example of mad is a plan to rob a police station.
An example of mad is someone getting worked up about possibly getting into trouble.
An example of mad is the comedy of George Carlin.