noun

• (historical) All the revenue obtained by a feudal lord from his vassals.
  "I will tell you. First, he comes regularly to take his rights of seigniorage, his rents, his taxes, his fourths of all the produce of his vineyards and arable lands on our Côte d'Or."
• (money) The revenue obtained directly by minting coin (difference between face value and cost of metal).
  "If Government, however, throws the expense of coinage, as is reasonable, upon the holder, by making a charge to cover the expense (which is done by giving back rather less in coin than has been received in bullion, and is called levying a seigniorage), the coin will rise, to the extent of the seigniorage, above the value of the bullion."
• (finance) The revenue obtained by the difference between interest earned on securities acquired in exchange for bank notes and the costs of producing and distributing those notes.