1. On the emotional level, there will be an undercurrent of unease, tension, boredom, or nervousness. 在你的情绪层次上，将会出现涌动的不安、紧张、无聊、焦躁。
2. More fundamental, perhaps, than any experience is the undercurrent of peace that has never left me since then. 也许最为基本的体验是子从那以后从未离开过我的平静的暗流。
3. When somebody confides in you, his words are spoken out of his mouth just like a clear, sweet and flowing river, whereas beneath the riverbed lurks a dirty undercurrent. 有的人，在面对你倾诉深情的时候，语言的表述像一条流淌的清亮甜美的大河，而在河床底下，却潜藏着一股污浊的暗流。
英英解释
n.
1. a subdued emotional quality underlying an utterance; implicit meaning
2. a current below the surface of a fluid
