(Ficus), in the Civil Law, the treasury of a prince or state; or that to which all things due to the public do fall. The word is derived from the Greek φίκος, "a great basket," used when they went to market.—By the civil law, none but a sovereign prince has a right to have a fisc or public treasury.

At Rome, under the emperors, the term aerarium was used for the revenues destined for support of the charges of the empire; the fiscus for those of the emperor's own family. The treasury, in effect belonged to the people, and the fiscus to the prince. Hence the goods of condemned persons, if appropriated to the use of the public, were laid publicari; if to the support of the emperor or prince, confisciari.