Webster's Revised Unabridged Dictionary · 1913

Contango

Contango (kon*tan"go) , noun

[Probably a corruption of contingent.]

1.
(Stock Exchange) The premium or interest paid by the buyer to the seller, to be allowed to defer paying for the stock purchased until the next fortnightly settlement day. [English]
2.
(Law) The postponement of payment by the buyer of stock on the payment of a premium to the seller. See Backwardation. — N. Biddle