mainspring

English

Etymology

From main +‎ spring.

Noun

mainspring (plural mainsprings)

1. The principal spring of a clockwork mechanism, that drives it by uncoiling.
   • 1922, Margery Williams, The Velveteen Rabbit

     He was wise, for he had seen a long succession of mechanical toys arrive to boast and swagger, and by-and-by break their mainsprings and pass away.

2. (figuratively) The most important reason for something.

   My daughter is the mainspring of my life.

Translations

the principal spring of a clockwork mechanism

• Egyptian Arabic: زمبلك‏‎ m (zambálek)
• French: ressort moteur m

• Manx: ard-lheimaghan m
• Turkish: zemberek (tr) m