What does "mainspring" mean?

The principal spring of a clockwork mechanism, which drives it by uncoiling.

What is a synonym for "mainspring"?

Common synonyms include: ambition, aspiration, basis, calling, cause, consideration.

noun

noun ·Uncommon ·Advanced level

Noun

1
The principal spring of a clockwork mechanism, which drives it by uncoiling.
"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
the most important spring in a mechanical device (especially a clock or watch); as it uncoils it drives the mechanism wordnet
3
The most important reason for, or element of, something. figuratively
"My daughter is the mainspring of my life."

"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."

From main + spring. For figurative sense, compare spring (“source, origin”).

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.