: one often in a position of authority who obligates himself or herself to act on behalf of another (as in managing money or property) and assumes a duty to act in good faith and with care, candor, and loyalty in fulfilling the obligation
: one (as an agent) having a fiduciary duty to another see also fiduciary duty at duty, fiduciary relationship compare principal
adj [Latin fiduciarius, from fiducia trust, transfer of a property on trust]
1 : of, relating to, or involving a confidence or trust [a guardian acting in his capacity]
2 : of or relating to a fiduciary or the position of a fiduciary [a bond]
Source: Merriam-Webster's Dictionary of Law ©1996. Merriam-Webster, Incorporated. Published under license with Merriam-Webster, Incorporated.