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 of fiat

• 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

Furthermore, direct $2,000 payments would almost certainly have to be approved by Congress and not done by executive fiat, according to York. —Zach Halaschak, The Washington Examiner, 12 Nov. 2025

Governments are increasingly eager to control the market through stablecoins backed by their own fiat currencies. —Evelyn Cheng, CNBC, 5 Nov. 2025

While traditional fiat currencies, such as the U.S. dollar, are issued by governments that can produce them as needed, bitcoin has a limited supply and is produced by computers. —Cheryl V. Jackson, IndyStar, 31 Oct. 2025

At the Greenwich Economic Forum in October, Dalio urged investors to allocate around 15% of their portfolios to gold, saying the metal’s surge reflects a shift away from debt assets and fiat currencies, reminding him of the 1970s. —Dave Smith, Fortune, 9 Oct. 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