fiduciary

American  

[fi-doo-shee-er-ee, -dyoo-] / fɪˈdu ʃiˌɛr i, -ˈdyu- /

noun

fiduciaries plural

1. Law. a person to whom property or power is entrusted for the benefit of another.

   All investment advisors registered with the Securities and Exchange Commission (SEC) must act as fiduciaries.

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adjective

1. Law. of or relating to the relationship of trust and good faith between a fiduciary and the person for whom the fiduciary acts.

   The executor of a will has a fiduciary duty to act in the best interest of the beneficiary.

   The banks do not assume any financial responsibility—they act in a fiduciary capacity only.

   The American Medical Association said that physicians have a fiduciary responsibility to patients.

2. depending on public confidence for value or currency, as fiat money.

fiduciary British  

/ fɪˈduːʃɪərɪ /

noun

1. a person bound to act for another's benefit, as a trustee in relation to his beneficiary

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adjective

1. 1. having the nature of a trust

   2. of or relating to a trust or trustee

Other Word Forms

• fiduciarily
  adverb
• nonfiduciary
  adjective

Etymology

Origin of fiduciary

First recorded in 1585–95; from Latin fīdūciārius “holding on trust; a trustee,” equivalent to fīdūci(a) “trust” + -ārius -ary

Explanation

A fiduciary is a person who holds assets in trust for someone else. That person has a fiduciary duty to take care of the money. Fiduciary comes from the Latin word fidere, "to trust." That's because a fiduciary is the person you trust to hold and watch over your assets until it's time for them to go to another designated person. For example, when a child's parents die, someone is chosen to look after the money left in the will until the child is old enough to manage it himself. Fiduciary can either be a noun to refer to the caretaker or an adjective to describe the trust.

Example Sentences

A broker is not a fiduciary of the beneficiary, meaning they don’t have to act in the enrollee’s best interest.

From MarketWatch • May 18, 2026

A fiduciary relationship creates a duty to act in the beneficiary’s interest, to act in good faith, and to use reasonable skill and diligence.

From The Wall Street Journal • May 3, 2026

The controller also sits on dozens of boards and commissions, playing the role of fiduciary watchdog when it comes to investing in schools, hospitals and transportation and the state’s pension funds.

From Los Angeles Times • May 1, 2026

“The board has always thoughtfully upheld its fiduciary responsibility and acted in the best interests of the students, staff and school.”

From The Wall Street Journal • Apr. 30, 2026

He prefers money as a concept and often uses terms such as annuity and fiduciary, words definitely not listed in the dictionary of mindless entertainment.

From "Me Talk Pretty One Day" by David Sedaris