English edit

Etymology edit

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

Noun edit

mainspring (plural mainsprings)

  1. (horology) The principal spring of a clockwork mechanism, which drives it by uncoiling.
  2. (figuratively) The most important reason for, or element of, something.
    My daughter is the mainspring of my life.
    • 2014 November 2, Paul Mason, “What Shakespeare taught me about Marxism”, in The Guardian[1]:
      But in the England of Shakespeare’s history plays, the mainspring of the system has broken down.

Translations edit