undercurrent
/ˈʌndəˌkʌrənt/noun
1- a current of water below the surface and moving in a different direction from any surface current.潜流; 底流。
1.1
- figurative an underlying feeling or influence, especially one that is contrary to the prevailing atmosphere and is not expressed openly〈喻〉暗流：
racial undercurrents.
种族主义暗流。