mainspring
Part of speech: noun
Usage examples "mainspring":
- Fortunately human nature does not readily yield to such behests, and so life is not robbed of its mainspring, and the whole machinery of human nature is not reduced to a chaotic bundle of useless wheels. - "The Law-Breakers", Ridgwell Cullum.
- Now that she was going back, she was without this mainspring of hope- her old studies and pursuits wearied her. - "Wife in Name Only", Charlotte M. Braeme (Bertha M. Clay).
- 3. A key- note of sincerity should be the mainspring of a well- built speech. - "The Century Handbook of Writing", Garland Greever Easley S. Jones.