Also found in: Legal.
In law, a person or company on whose behalf an agent acts, but who is not revealed. That is, the agent does not tell any other party who the undisclosed principal is. This secrecy may sometimes be necessary for a variety of reasons, such as the avoidance of some controversy. However, due to the secrecy, in the event of a dispute, the agent for the undisclosed principal may be held personally liable for the principal's actions.