This is the 936th most frequent French word.
moteur
Engine or motor.
Here, "moteur" refers specifically to the mechanical device that powers a car, illustrating a literal usage.
Le moteur de la voiture est en panne.
The car's engine is broken.
In this figurative usage, "moteur" symbolizes a driving force or something that propels progress or development.
L'innovation est le moteur du progrès.
Innovation is the engine of progress.
In this professional context, "moteur" describes the specific field related to the design and engineering of engines.