What does fiat mean?
A fiat is an authoritative command or decree issued by someone holding power — a monarch, legislature, court, or executive — typically without consulting those affected or allowing appeal. The word entered English in the early seventeenth century from Latin, where fiat means "let it be done," the third-person singular present subjunctive of facere, "to do" or "to make." In modern usage it most often appears in the fixed phrase "by fiat," signalling that a decision rests on raw authority rather than deliberation or consensus, and it frequently carries a note of criticism toward high-handed governance. Economists use a second sense in "fiat money": currency that a government declares legal tender without tying its value to gold or any other commodity. Nearly all circulating money today — dollars, pounds, euros — is fiat in this technical sense. The word's blend of classical pedigree and contemporary relevance makes it useful for writers discussing power, law, and finance alike.
An official order or decree, especially one issued by a ruler or authority without consultation or right of appeal.
"The boundary was redrawn by judicial fiat."
Most often found in the fixed expression "by fiat."
Currency that a government has declared legal tender without backing it in a physical commodity such as gold or silver.
"Fiat money depends entirely on public trust in the issuing government."
Chiefly used in economics and monetary policy discussions, usually as the modifier in "fiat money" or "fiat currency."
The plural is regular but uncommon; "fiat" is frequently treated as a mass noun in the phrase "by fiat."
"The archives preserve the fiats of three successive kings."
"Fiat" is Latin for "let it be done" — the same phrase that once launched empires now names the money in your wallet.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of fiat
Fiat comes directly from Latin fiat, meaning "let it be done" or "let there be," the third-person singular present subjunctive of facere, "to do" or "to make." The phrase famously opens the account of creation in the Latin Vulgate — "dixitque Deus... fiat lux," "and God said, let there be light." English adopted the word as a noun in the early seventeenth century to denote an authoritative command, retaining its Latinate force of something brought into existence purely by being decreed. It shares this root with English words built on the related stems of facere and fides, such as "definite," "confide," and "fiduciary."
How fiat is actually used
The word carries a formal, often disapproving connotation, implying arbitrary exercise of power. The phrase "by fiat" is especially common in political and administrative contexts, while "fiat money" belongs chiefly to economic discourse.
Easily confused with fiat
The Italian carmaker Fiat takes its name from the acronym Fabbrica Italiana Automobili Torino and is unrelated in meaning, though both trace back to Latin roots.
Fiasco means a complete failure; despite a superficially similar opening, it has no connection to the authoritative command sense of fiat.