The Collaborative International Dictionary of English v.0.48:

Sumptuary \Sump"tu*a*ry\, a. [L. sumptuarius, fr. sumptus
   expense, cost, fr. sumere, sumptum, to take, use, spend; sub
   under + emere to take, buy: cf. F. somptuaire. See Redeem.]
   Relating to expense; regulating expense or expenditure.
   --Bacon.
   [1913 Webster]

   Sumptuary laws or Sumptuary regulations, laws intended to
      restrain or limit the expenditure of citizens in apparel,
      food, furniture, etc.; laws which regulate the prices of
      commodities and the wages of labor; laws which forbid or
      restrict the use of certain articles, as of luxurious
      apparel.
      [1913 Webster]