(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. Hence: The chief or most powerful motive; the efficient cause of action.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). mainspring. Retrieved September 25, 2026, from http://smartdefine.org/mainspring/definitions/2029891 |
| Chicago | Webster's. 2011. "mainspring" http://smartdefine.org/mainspring/definitions/2029891 (accessed September 25, 2026). |
| Harvard | Webster's 2011, mainspring, Smart Define, viewed 25 September, 2026, <http://smartdefine.org/mainspring/definitions/2029891>. |
| MLA | Webster's. "mainspring" 27 May 2011. Web. 25 September 2026. <http://smartdefine.org/mainspring/definitions/2029891> |