Webster’s Revised Unabridged Dictionary · 1913
Contango
Con·tan′go (kŏn·tăn̲′gō), n.; pl. Contangoes (#). [Prob. 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. [Eng.]
2. (Law) The postponement of payment by the buyer of stock on the payment of a premium to the seller. See Backwardation. N. Biddle.