the principal spring of a clockwork mechanism, that drives it by uncoiling

listen to the pronunciation of the principal spring of a clockwork mechanism, that drives it by uncoiling
İngilizce - Türkçe
İngilizce - İngilizce
mainspring

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.

the principal spring of a clockwork mechanism, that drives it by uncoiling