Seigniorage

Webster's Dictionary of the English Language

·noun A share of the receipts of a business taken in payment for the use of a right, as a copyright or a patent.

II. Seigniorage ·noun Something claimed or taken by virtue of sovereign prerogative; specifically, a charge or toll deducted from bullion brought to a mint to be coined; the difference between the cost of a mass of bullion and the value as money of the pieces coined from it.