mainspring

Meanings

1. 1
   noun

   the chief motive, source, or driving force behind an action or development

   Public trust was the mainspring of the reform movement's early success.

2. 2
   noun

   the principal coiled spring in a clock, watch, or similar mechanism, which supplies its power as it unwinds

   The watch stopped when its mainspring snapped inside the case.

A compound of main, 'principal,' and spring. It first named the principal spring that powers a clockwork mechanism; the figurative sense developed by treating a dominant motive or source of energy as the spring that sets events in motion.

Topics