A financial side or leg of a trade that is not fixed in advance, but is dependent on the value of some observable (usually an index) at a pre-agreed time related to the delivery date

Detail

Most trades involve at least two legs or sides, in a straightforward physical Forward contract one side is the physical delivery of the commodity, the other is the cash payment in settlement of the commodity delivered

In an indexed forward, or floating forward, the cash side is not fixed in advance, but related to an index (usually published daily), and generally fixed in daily or monthly either at the daily price or the average of the daily-published monthly price