What is a term for an explosive substance that acts as a driving force?

The correct term for an explosive substance that acts as a driving force is "Propellant." Propellants are materials that, when ignited, produce gases that expand rapidly, providing thrust and driving force, particularly in rockets, firearms, and various propulsion systems. They play a crucial role in launching projectiles or moving vehicles by converting stored energy into kinetic energy.

The other terms do not relate to explosive substances or driving forces. "Cordially" refers to a friendly or warm manner, which has no connection to propulsion or explosives. "Magnate" usually refers to a person of great influence or power in a particular industry, while "Conciliatory" describes actions intended to placate or pacify. Thus, they do not pertain to the concept of an explosive driving force in the context of this question.