Fiduciary Meaning: Here’s What It Means and How To Use It

This guide will show you the meaning of the word fiduciary, its origin, how it’s used, examples, and synonyms. Click here to learn more.

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Sometimes we hear words off and on in our lives that we assign a meaning to from context clues. Taking the time to learn the true meanings of words enriches our vocabularies and gives us a deeper understanding of the words we hear in context. Fiduciary might not be part of your everyday vocabulary, but this guide will help you learn more about what it means, where it comes from, and how to use it.

What Does Fiduciary Mean?

Fiduciary has a few definitions. It can be used as either an adjective or a noun. 

As a noun, a fiduciary is a person that property or power has been entrusted to for the benefit of another person. The plural form of the word is fiduciaries. You’ll see this word as a noun most often in law or legal matters.


  • Investment advisors who are registered with the Securities and Exchange Commission (SEC) are expected to act as fiduciaries. 
  • Her friend became her fiduciary when she became ill and could no longer act on her own behalf.

As an adjective, fiduciary describes the nature of the relationship between the trusted person or the fiduciary and the person for whom their actions are carried out. As with the noun, you’ll see this most often in law and legal matters.

  • The power of attorney bestows on her an expectation of fiduciary duty to act in her friend’s best interest when she is unable to make decisions for herself.
  • Your physician has a fiduciary responsibility to give you medical care.

In legal matters, a person with a fiduciary duty must act in ways that will be beneficial to someone else. Most often, this responsibility refers to financial decisions that are made on the behalf of the beneficiary.

Additionally as an adjective, fiduciary describes the dependency on public confidence to assign value as with fiat money. 

What Is the Origin of Fiduciary?

Fiduciary can be traced to the 1640s. In the late 16th century, it would have been used as an adjective to describe something that inspires trust or credentials. The word comes from the Latin fiduciarius which comes from the Latin fiducia and the Latin fidere. The words meant:

  • Fiducia – trust
  • Fidere – to trust

As it has evolved over time, it’s interesting to see how the word has maintained so much of the meaning from its word origins. 

How Do We Use Fiduciary?

Fiduciary is commonly used as a legal term. A fiduciary is a person with a legal or ethical relationship to another person, a party, or a group of persons or parties that is based on trust. A fiduciary will often be charged with the responsibility to prudently attend to the assets or care of the money that belongs to the other person. 

A fiduciary can even be a company such as a corporate trust company or a department of a company like the trust department of a bank. The company or corporate entity acts in a fiduciary capacity in the best interests of a client. 

Some common roles that can put a person in a fiduciary position include:

  • Lawyers
  • Corporate officers 
  • Guardians
  • Financial advisors
  • Trustee of a trust 
  • Asset managers
  • Money managers
  • Insurance agents
  • Broker

Fiduciary duties create a reliance of the beneficiary on the honesty of their potential advisors. For example, a fiduciary financial advisor must make choices in good faith with a certain adherence to their duty of care and duty of loyalty to make decisions that accept a risk tolerance that is in a beneficiary’s best interest. In other words, don’t play fast and loose with someone else’s assets.

On a bigger scale, corporate officers or company executives need to make business decisions that meet the fiduciary standard set forth by the shareholders of the company. 

Certain roles are considered fiduciaries under the law and certain statutes. For example, money managers charged with the protection of certain endowments, pension plans, and other assets are legally required to act in a fiduciary capacity on behalf of the beneficiary’s best interest. 

For brokers, depending on the situation, they may be held to a fiduciary standard or a suitability standard. Under the suitability standard, the broker must reasonably believe that a transaction is suitable for their client. With a fiduciary standard, their actions must meet common law expectations of acting in good faith on behalf of the client.

People with fiduciary responsibility are ethically obligated to act in the beneficiary’s best interest. This is something to consider when accepting a role as a fiduciary.

Are There Any Synonyms for Fiduciary?

Synonyms help us express the same meaning using different words. Here are a few synonyms for the word fiduciary:

  • Trustee
  • Curator
  • Guardian
  • Depositary
  • Confident
  • Fiducial
  • Trustful
  • Trusty

Are There Any Antonyms for Fiduciary?

Antonyms are a useful tool when you need to express the opposite meaning of a word. Here are a few antonyms for the word fiduciary:

  • Unreliable
  • Unconvincing
  • Implausible
  • Questionable
  • Improbable
  • Unlikely
  • Unreliable

Examples of Fiduciary

These examples will help you use and understand the use of the word fiduciary in the future. Here are a few examples of fiduciary in a sentence for reference:

  • She had a fiduciary duty to do the right thing and act in the best interests of her clients.
  • The power of attorney gave them a fiduciary relationship.
  • The court ruled that the shareholders had a case because of the breach of fiduciary duty.
  • The judge made a fiduciary rule to protect the ward of the state.
  • Directors of corporations are fiduciaries.
  • The plaintiff claimed the fiduciary should have had a more critical eye when making decisions.

The Last Word

Definitions, etymology, and examples of using words adds depth and understanding of words in our vocabulary. Now that you know what fiduciary means, you’ll understand the word when you hear it, and you’ll be better prepared to use it in a sentence.


  1. Fiduciary Definition & Meaning | Merriam-Webster 
  2. Fiduciary Duty | Wex | US Law | LII / Legal Information Institute | 
  3. Suitability |