Demonstrator

A demonstrator may be:
 * A person performing a demonstration, such as to explain science or technology
 * A person demonstrating a product for sale live or in an infomercial
 * An attendee at a political rally
 * An academic rank
 * A vehicle adapted to emergency service specification, and issued to locations for use as a prospective emergency vehicle if adopted to that workforce either police, ambulance or fire.
 * A fountain pen with a transparent body originally used so dealers could show customers how they worked. See Demonstrator pen
 * Demonstrator (film)