mainspring

[meyn-spring]

SEE MORE SYNONYMS FOR mainspring ON THESAURUS.COM

noun

the principal spring in a mechanism, as in a watch.

the chief motive power; the impelling cause.

Origin of mainspring

First recorded in 1585–95; main¹ + spring

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for mainspring

emotion, motivation, impulse, influence, idea, aim, intention, intent, rationale, consideration, passion, feeling, cause, provenance, element, motive, source, connection, ancestry, ancestor

Examples from the Web for mainspring

Historical Examples of mainspring

Perhaps this had originally been the mainspring of the understanding between them.
Little Dorrit
Charles Dickens
How's she goin' to cock that gun, an' the mainspring fifteen pounds resistance?'
Faro Nell and Her Friends
Alfred Henry Lewis
That need is the mainspring of life, the key to heaven, and the root of all evil.
Olive in Italy
Moray Dalton
The words were an echo of those which formed the mainspring of the Admiral's life.
Saint Bartholomew's Eve
G. A. Henty
For that was really the mainspring of her fantastic actions.
The Good Soldier
Ford Madox Ford

British Dictionary definitions for mainspring

mainspring

noun

the principal power spring of a mechanism, esp in a watch or clock

the chief cause or motive of something

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for mainspring

1590s, of watches, clocks, etc., from main (adj.) + spring (n.3). Figurative use from 1690s.