Fi"at (?), n. [L., let it be done, 3d pers. sing., subj. pres., fr. fieri, used as pass. of facere to make. Cf. Be.]
1.
An authoritative command or order to do something; an effectual decree.
His fiat laid the corner stone.
Willis.
2. Eng.Law (a)
A warrant of a judge for certain processes.
(b)
An authority for certain proceedings given by the Lord Chancellor's signature.
Fiat money, irredeemable paper currency, not resting on a specie basis, but deriving its purchasing power from the declaratory fiat of the government issuing it.
© Webster 1913.