FIAT, practice. An order of a judge, or of an officer, whose authority, to be signified by his signature, is necessary to authenticate the particular acts.

Source: Bouvier's Law Dictionary, Revised 6th Ed (1856)
 

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]

Source: The Collaborative International Dictionary of English v.0.48
 

40 Moby Thesaurus words for "fiat": appointment, authority, authorization, brevet, bull, certification, clearance, countenance, declaration, decree, decree-law, decreement, decretal, decretum, dictum, diktat, edict, edictum, empowerment, enabling, endorsement, enfranchisement, entitlement, ipse dixit, law, ordinance, ordonnance, proclamation, pronouncement, pronunciamento, ratification, rescript, rule, ruling, sanction, senatus consult, senatus consultum, ukase, warrant, warranty

Source: Moby Thesaurus II by Grady Ward, 1.0
 

fiat

Source: WordNet (r) 2.0
 

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.

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.

Source: Webster's Revised Unabridged Dictionary (1913)