名詞 mainspring:

1. the most important spring in a mechanical device (especially a clock or watch); as it uncoils it drives the mechanism

1. The cylinder within the mechanism of a timepiece that contains the mainspring.
   發(fā)條盒一圓柱形物，內(nèi)裝含有主發(fā)條的表的零件
2. Her jealousy is the mainspring of the novel's plot.
   這部小說情節(jié)中貫穿了她的忌妒之心。

main.spring

n.（名詞）
The principal spring in a mechanical device, especially a watch or clock, that drives the mechanism by uncoiling.
主彈簧：一個機械裝置中尤其是手表或鐘表通過繞旋反解來驅動機械的彈簧
The chief motivating force:
主要推動力：
例句：
the mainspring of a reform movement.
改革運動的主要推動力