Reactive-thrust meaning

Thrust generated through the expulsion of propellant or exhaust in a particular direction, as by a rocket engine.

Thrust generated by an engine through the rapid expulsion of propellant or its exhaust in a particular direction. By Newton's third law, the force required to expel the propellant or exhaust is counterbalanced by an equal and opposite force, driving the engine (and its vehicle) in the opposite direction.