keystone
英 ['ki?st??n]
美['ki'ston]
- n. 主旨，基本原則；[建] 楔石
英英釋意
- 1. a central cohesive source of support and stability;
- "faith is his anchor"
- "the keystone of campaign reform was the ban on soft money"
- "he is the linchpin of this firm"
- 2. the central building block at the top of an arch or vault