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

Stablecoins are cryptos that are pegged to fiat currencies, such as the dollar. —Brian Evans, CNBC, 4 Aug. 2025

Why gold demand surged While the dollar or the euro isn’t going away anytime soon, Doshi said the demand for real hard assets that complement fiat currency rose over the last few decades as global debt and governments’ share of that debt has increased. —Rachel Barber, USA Today, 2 Aug. 2025

The startup operates a mobile wallet for enterprises, which allows domestic and cross-border payment as well as foreign exchange of multiple fiat currencies. —Zinnia Lee, Forbes.com, 30 July 2025

When a consumer pays with crypto, the funds are automatically converted into fiat or PayPal’s PYUSD stablecoin for deposit in the merchant’s account. —Bloomberg, Mercury News, 28 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