1. the principal springs in mechanical clocks or watches that store energy to power the mechanism
2. the most important or influential elements that cause or drive something
Usage: figurative

Examples

• The antique clock stopped working when its mainsprings broke.
• Watchmakers must carefully wind the mainsprings during repairs.
• Economic opportunity and political freedom were the mainsprings of westward expansion.
• Education and hard work are the mainsprings of success in most careers.
• The mainsprings of the old pocket watch needed replacement after decades of use.
• Innovation and competition serve as the mainsprings of technological progress.