Mainspring

Pronunciation: /ˈmeɪnˈspɹɪŋ/

Mainspring (noun)

  1. A strong coiled spring inside a clock or watch that stores energy and helps the parts move.
  2. The main reason something happens; the force that makes a person or system keep working.

Examples

  • The mainspring powers the clock when it is wound.
  • The clock stops if the mainspring breaks.