Advertisement

mainspring (n.)

1590s, "principal spring of a mechanism" (of a watch, clock, gun, etc.), from main (adj.) + spring (n.3). Figurative meaning "impelling cause or motive of any action" is from 1690s.

Others are reading

Advertisement
Advertisement
Definitions of mainspring from WordNet

mainspring (n.)
the most important spring in a mechanical device (especially a clock or watch); as it uncoils it drives the mechanism;
From wordnet.princeton.edu