Mainspring
English Meaning
The principal or most important spring in a piece of mechanism, especially the moving spring of a watch or clock or the spring in a gunlock which impels the hammer. Hence: The chief or most powerful motive; the efficient cause of action.
- The principal spring in a mechanical device, especially a watch or clock, that drives the mechanism by uncoiling.
- The chief motivating force: the mainspring of a reform movement.