from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The principal spring in a mechanical device, especially a watch or clock, that drives the mechanism by uncoiling.
- n. The chief motivating force: the mainspring of a reform movement.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The principal spring of a clockwork mechanism, that drives it by uncoiling.
- n. The most important reason for something.
from the GNU version of the Collaborative International Dictionary of English
- n. The principal or most important spring in a piece of mechanism, especially the moving spring of a watch or clock or the spring in a gunlock which impels the hammer.
from The Century Dictionary and Cyclopedia
- n. The principal spring of any piece of mechanism, as, in a gun-lock, the spring which operates the hammer; specifically, the coiled spring of a watch or other timepiece.
- n. The impelling cause of any action; the inciting motive.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. the most important spring in a mechanical device (especially a clock or watch); as it uncoils it drives the mechanism
Sorry, no etymologies found.