mainspring
Definition
The main spring that powers a clock or watch; metaphorically, a chief source of motivation or energy.
日本語 時計や腕時計の主力スプリング、または主な動機源
Example
"Curiosity is the mainspring of scientific discovery."
The main spring that powers a clock or watch; metaphorically, a chief source of motivation or energy.
日本語 時計や腕時計の主力スプリング、または主な動機源
"Curiosity is the mainspring of scientific discovery."