fiat

Etymology

It is borrowed from Latin fīat (“let it be done, let there be made”),^[2][3][4][5] the third person singular present subjunctive of fīō (“to become, to be done”),^[2][3][6][7] which served as the passive of faciō (“to make, do”).^[2][3][5][7] The Latin word opened Medieval Latin proclamations and commands,^[3][8] and Barnhart and the American Heritage Dictionary take it into English through Medieval Latin.^[9][4] The verb is from Proto-Indo-European *bheuə- (“to be, exist, grow”),^[4][3] and is related to fuī (“I have been”),^[6][10][11] to Ancient Greek φύω (phúō, “to cause to grow”)^[9] and to English be.^[9][6][11] Klein also finds it in the second element of ratafia.^[6]

Earliest recorded meaning

A command that brings something into being, with reference to fiat lux, "let there be light", in the Vulgate's Genesis: before 1631, in John Donne's poem "The Storm".^[2][9] Barnhart notes an earlier use as a partly Latin word in a document of about 1384,^[9] and the Shorter Oxford and the Oxford Dictionary of English date the noun to late Middle English.^[12][13]

Semantic evolution

The legal and administrative sense came from the word fiat itself, written on a document, or a formula containing it, by which an authority approved a request or arrangement; the OED records this from 1647.^[2][12] From there it widened to any authoritative pronouncement or order (before 1750),^[2][3] and in current use it often means an arbitrary decree, as in "by government fiat".^[4][14] The creative sense, after God's words in Genesis 1:3,^[3] survives in the sense of a command or act of will that brings something about.^[7][14] In the 1870s American English formed fiat money, paper money made legal tender by government decree without being convertible into coin.^[15][7][14] A verb fiat, to sanction with a fiat, is recorded from 1831.^[2][12]

Timeline

• c. 1384 – a partial Latinism in a document.^[9]
• before 1631 – a creative command, after fiat lux, in Donne.^[2][9]
• 1647 – a formal sanction expressed by the word fiat.^[2]
• before 1750 – an authoritative decree, command or order.^[2][3]
• 1831 – verb, to sanction by a fiat.^[2]
• 1876 – fiat money.^[7]

Meanings

Noun

1. An authoritative or arbitrary order or decree: The new fees were imposed by ministerial fiat.^[4][14][2]
2. Official sanction or authorization; permission: The council could not act without the governor's fiat.^[4][14][7]
3. A command or act of will that creates something, as if without further effort, after fiat lux, "let there be light".^[7][14][2]

Adjective

1. Created or established by decree rather than by intrinsic worth, as in fiat money, paper money that is not convertible into coin.^[7][14]

Verb

1. To sanction or authorize by a fiat.^[2][12]

Word family

• fiat lux
• fiat money

Related words

• be
• ratafia
• fact

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m n Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f g h Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b c d e f The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
5. ^ a b Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
6. ^ a b c d Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
7. ^ a b c d e f g h Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
8. ^ Weekley, Ernest (1921), An Etymological Dictionary of Modern English, London: John Murray
9. ^ a b c d e f g Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
10. ^ Partridge, Eric (1966), Origins: A Short Etymological Dictionary of Modern English, 4th ed., London: Routledge & Kegan Paul
11. ^ a b Skeat, Walter W. (1911), A Concise Etymological Dictionary of the English Language, new ed., Oxford: Clarendon Press
12. ^ a b c d Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
13. ^ Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
14. ^ a b c d e f g Collins English Dictionary (2023), Glasgow: HarperCollins
15. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House