From The Collaborative International Dictionary of English v.0.48 [gcide]:
Fiat \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.
[1913 Webster]
His fiat laid the corner stone. --Willis.
[1913 Webster]
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.
[1913 Webster]
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.
[1913 Webster]
From WordNet (r) 3.0 (2006) [wn]:
fiat
n 1: a legally binding command or decision entered on the court
record (as if issued by a court or judge); "a friend in New
Mexico said that the order caused no trouble out there"
[syn: decree, edict, fiat, order, rescript]