driving force; driving power
Refers to the force or power that drives something forward, often used in mechanical, economic, or metaphorical contexts.
The engine's driving force is transmitted to the wheels.
The driving force behind economic growth is technological innovation.
Compound of 駆動 (drive, propulsion) and 力 (power, force). The exact historical derivation is uncertain, but the word is a straightforward Sino-Japanese compound.