adjective
Definition: Relating to a person or organization that has the responsibility to manage someone else's money or property with care and trust.
Example: The lawyer acted in a fiduciary capacity, ensuring that the client's interests were protected.
noun
Definition: A person or organization that has the legal responsibility to manage money or property for another person or group, acting in their best interest.
Example: The lawyer acted as a fiduciary for his client, ensuring that all decisions were made in her best interest.