primemover
nounUK /ˌpraɪm ˈmuːvə/
US /ˌpraɪm ˈmuːvər/
The first thing that makes something happen.
The sun is the primemover that keeps the water cycle going.
RELATED WORDS
OTHER MEANINGS
2. The main force or machine that provides power to make something work.
The engine is the primemover of the whole train.
3. A person who starts a big project or change.
She was the primemover behind the new park in town.
4. The original source of energy or motion in a system.
Wind is the primemover for the sailboat.