- fiat⇄fiat, noun, verb.
- fiat⇄noun 1. an authoritative order or command; decree.
Ex. to determine by the fiat of the king alone the course of national policy (William Stubbs).
2. an authoritative sanction; authorization. - fiat⇄v.t. 1. to attach a fiat to; sanction.
2. to declare by a fiat.