fiduciary

IPA/fɪˈdjuːʃəri/
KK[fədˈuʃiˌɛri]IPA/fɪˈduːʃieri/

fiduciary — adjective

  • fiduciarypositive
  • more fiduciarycomparative
  • most fiduciarysuperlative

1. describing a duty where one person must look after another person's money or pro

1.adjectiveC2
Definition

describing a duty where one person must look after another person's money or property and put that other person's interests first.

Example

As trustee of the family fund, Xiu had a fiduciary duty to her younger brothers.

fiduciary + duty — most common collocation

The bank failed in its fiduciary role when it sold risky shares to elderly clients.

fiduciary + role / responsibility

Common collocations
  • fiduciary duty
  • fiduciary responsibility
  • fiduciary obligation
  • fiduciary role
  • fiduciary relationship
  • breach of fiduciary duty
Synonyms
  • trust-based

    plainer, everyday register; works in general writing

  • custodial

    emphasises physically holding or guarding the asset rather than legal duty

Grammar Patterns

fiduciary + noun (duty, responsibility, role)

Usage Note

Almost always used before a noun (fiduciary duty / responsibility / relationship / role). Subject is usually a person or organisation with formal power over another party's money or property — a trustee, lawyer, director, or financial adviser.

Common Mistakes

The agreement is fiduciary.
The agreement creates a fiduciary duty.
fiduciary is used before a noun, not after a linking verb.

2. describing a relationship that the law treats as one of trust — for example betw

2.adjectiveC2
Definition

describing a relationship that the law treats as one of trust — for example between a lawyer and a client, or a guardian and a child — where one side must act honestly for the other.

Example

A lawyer stands in a fiduciary relationship with the client who hires her.

fiduciary + relationship — defining usage

Emre acted in a fiduciary capacity when he managed his grandmother's medical accounts.

in a fiduciary capacity (fixed legal phrase)

Common collocations
  • fiduciary relationship
  • fiduciary capacity
  • fiduciary position
  • in a fiduciary capacity
Synonyms
  • trust-based

    lay equivalent — use in general writing where 'fiduciary' would feel too legal

Antonyms
  • arm's-length

    describes a relationship with no special duty of care — the opposite legal framing

Grammar Patterns

fiduciary + noun (relationship, capacity, trust)

Usage Note

Distinguish from sense 1: sense 1 names the specific DUTY (what the person must do); sense 2 names the RELATIONSHIP or capacity in which that duty exists. Often appears in the fixed phrase 'in a fiduciary capacity'.

fiduciary — noun

Word family

  • fiduciarily
    adverbC2

Synonym discussion

Sense: noun/1

All four words name someone who looks after another person's property, but the legal scope differs sharply. 'Fiduciary' is the broadest term — any party (lawyer, director, financial adviser, trustee) who owes a duty of loyalty to a beneficiary. A 'trustee' is a specific type of fiduciary, formally appointed to manage assets held in a trust under written terms. A 'custodian' guards or physically holds an asset (often securities at a bank), but does not necessarily owe the wider loyalty duty that a fiduciary does. An 'executor' is a fiduciary too, but only for one job: carrying out a deceased person's will. So in practice, every trustee, custodian, and executor is a fiduciary, but not every fiduciary is a trustee — for example, Iris's financial adviser is a fiduciary without being her trustee. All four belong to formal legal register.

fiduciary ↗trustee ↗custodian ↗executor ↗

Common collocations

Nouns

  • fiduciary duty
  • fiduciary responsibility
  • fiduciary obligation
  • fiduciary relationship
  • fiduciary capacity
  • fiduciary role
  • breach of fiduciary duty

Phrases

  • in a fiduciary capacity
  • act as a fiduciary
  • owe a fiduciary duty

Prepositions

  • fiduciary to (a person)
  • fiduciary for (a beneficiary)

Etymology

LatinEnglish

From Latin 'fiducia' meaning trust or confidence, itself from 'fidere' (to trust). The English word entered legal writing in the 17th century to describe a relationship where one party places trust in another to act honestly with their property or affairs. The same root gives English 'confide', 'fidelity', and 'faith'.