Source : Webster's Revised Unabridged Dictionary (1913)

Backwardation \Back`war*da"tion\, n. [Backward, v. i.+ -ation.]
   (Stock Exchange)
   The seller's postponement of delivery of stock or shares,
   with the consent of the buyer, upon payment of a premium to
   the latter; -- also, the premium so paid. See {Contango}.
   --Biddle.