fiduciary

Etymology

It is borrowed from Latin fīdūciārius (“held in trust”),^[2][3][4][5] possibly through fiduciaire,^[6][2] from fīdūcia (“trust, confidence”),^[2][7][8] from fīdō (“to trust”),^[7][6][9] from Proto-Indo-European *bheidh- (“to trust, confide, persuade”).^[7] In law the Latin noun was a deposit or pledge, and in Roman law the transfer of a right to someone who had to hand it back later or on a condition.^[7][2] The noun in the sense of a trustee is from the Medieval Latin noun fiduciarius (“trustee”), from the adjective.^[6]

Earliest recorded meaning

As a noun, something that secures trust, credentials: 1593, in R. Bancroft's Daungerous Positions.^[2][10][9]

Semantic evolution

The noun was soon used of a person, a trustee (1631),^[2][6][4] and briefly in theology of one who equated saving faith with confidence in one's own salvation (1654–1684).^[2] The adjective first meant "showing trust or reliance" (1640),^[2] the sense Johnson (1755) gave first as "confident; steady; undoubting".^[11] From 1647 it meant holding something in trust, from before 1641 of things held in trust.^[2][6][7] Since 1795 it has also meant relating to trustees and trusteeship.^[2] In the 19th century it was used of paper money whose value rests on public confidence (1878).^[2][4]

Timeline

• 1593 – noun, something that secures trust; credentials (obsolete).^[2][10]
• 1631 – noun, a trustee.^[2][6][4]
• 1640 – adjective, showing trust or reliance (obsolete by 1680).^[2]
• before 1641 – held or given in trust.^[2][4]
• 1647 – of a person, holding something in trust.^[2]
• 1795 – relating to a trustee or trusteeship.^[2]
• 1878 – of paper money, depending on public confidence.^[2]

Meanings

Adjective

1. (law) Relating to or involving a trust or a trustee: a fiduciary duty to the shareholders.^[8][4][2]
2. Holding or held in trust.^[4][2]
3. Of paper currency, depending for its value on public confidence.^[4][2]
4. (obsolete, 1640–1680) Showing trust or reliance; confident.^[2][11]

Noun

1. (law) A person or company bound to act for another's benefit, such as a trustee.^[8][4][2]
2. (obsolete, 1593) Something that secures trust; credentials.^[2][10]

Word family

• fiduciarily
• nonfiduciary

Related words

• fiducial
• faith
• fidelity
• confide
• confidence

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m n o p q r s t u v w x Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
4. ^ a b c d e f g h i Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
5. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
6. ^ a b c d e f Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
7. ^ a b c d e Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
8. ^ a b c Collins English Dictionary (2023), Glasgow: HarperCollins
9. ^ a b Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
10. ^ a b c Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
11. ^ a b Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.