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

While stablecoins promise faster, cheaper cross-border payments, the real challenge lies in navigating complex licensing requirements and integrating with traditional fiat systems. — Boaz Sobrado, Forbes.com, 23 June 2026

Baldwin’s position was that the centrality of slavery and racial subjugation in American history could not simply be reversed by legislative fiat. — Hua Hsu, New Yorker, 22 June 2026

Bitcoin is by far the largest crypto token by market capitalization, and its proponents frequently tout it as a form of digital gold that can serve as a hedge against inflation-prone fiat currencies. — Jack Kubinec, Fortune, 26 May 2026

Anthropic is suing the Defense Department and the relevant federal agencies to undo the fiats. — Jared Perlo, NBC news, 29 Apr. 2026

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

Rhymes for fiat

• panchayat

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