kingpin
/ˈkɪŋpɪn/noun
1- a main or large bolt in a central position大销; 主销。
1.1
- a vertical bolt used as a pivot中枢立轴。
1.2
- a person or thing that is essential to the success of an organization or operation主脑人物：
the kingpins of the television industry.
电视产业的主脑人物。