fiat

noun

fi·​at ˈfē-ət 

-ˌat,

-ˌät;

ˈfī-ət,

-ˌat 

1

: an authoritative or arbitrary order : decree

government by fiat

2

: an authoritative determination : dictate

a fiat of conscience

3

: a command or act of will that creates something without or as if without further effort

According to the Bible, the world was created by fiat.

Synonyms

• decree
• edict
• ruling
• directive

Examples of fiat in a Sentence

He runs the company by fiat.

the school principal issued a fiat that caps were not to be worn inside the school, and that was that

Recent Examples on the Web

For Florida residents, the law offers a choice: use traditional fiat currency with its flexibility and federal backing, or turn to gold and silver, which offer protection from inflation but lack the agility of modern economic instruments. —Luciano Duque, The Orlando Sentinel, 5 July 2025

The Senate approved the stablecoin bill late last month, establishing a regulatory framework for these digital currencies that are pegged to the U.S. dollar or other fiat currencies. —Trefis Team, Forbes.com, 3 July 2025

Stablecoins, which are digital assets usually pegged to fiat currencies, have grown in popularity. —Preston Fore, Fortune, 2 July 2025

For decades, the U.S. has operated on fiat currency, and while federal law already recognizes U.S. gold and silver coins as legal tender, their actual commercial use has been rare and logistically challenging. —James Bickerton, MSNBC Newsweek, 2 July 2025

Word History

Etymology

Latin, let it be done, 3rd singular present subjunctive of fieri to become, be done — more at be

First Known Use

circa 1631, in the meaning defined at sense 3

Phrases Containing fiat

• fiat money

Kids Definition

fiat

noun

fi·​at ˈfē-ət  -at 

-ät;

ˈfī-ət,

-at

: an order from someone in charge

Legal Definition

fiat

noun

fi·​at ˈfē-ˌät, -ˌat, -ət; ˈfī-ˌat 

1

: decree

2

: an authoritative but arbitrary order

a brazen act of judicial fiat

—L. H. Tribe