Definition of backload:
(n) :
A load carried on the return journey of a delivery vehicle.
(v) :
(transport) To load (cargo, shipment, etc.) after unloading has been completed.
(v) :
To load toward the back, or towards the end of a period.
(v) :
(transitive, military) To transport further toward the rear of the theater of war.
(v) :
To fill a syringe with solution from the plunger end of the barrel.