noun · a political or strategic alliance between powers or nations

这三个国家在国际事务中形成了一个政治轴心。

noun · the physical shaft or spindle on which a wheel or mechanical part rotates

机器的轴心因为过度磨损需要更换。

noun · the core, pivot, or most essential part of a system, organization, or concept

他是整个研究团队的轴心人物。