from
The Collaborative International Dictionary of English v.0.48
Contango \Con*tan"go\ (k[o^]n*t[a^][ng]"g[-o]), 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.]
[1913 Webster]
2. (Law) The postponement of payment by the buyer of stock on
the payment of a premium to the seller. See
{Backwardation}. --N. Biddle.
[1913 Webster]