Fiat

Part of speech: noun (n.)

1. An authoritative command or order to do something; an effectual decree. His fiat laid the corner stone. Willis.

2. A warrant of a judge for certain processes.

3. 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.