noun, noun or participle which takes 'suru', intransitive verb
undercurrent; bottom current
Refers to a current flowing beneath the surface of water, or figuratively to an underlying trend or hidden influence.
この海域には強い底流があるので、泳ぐときは注意が必要だ。
There is a strong undercurrent in this area, so you need to be careful when swimming.
社会の底流には、大きな変化の兆しが感じられる。
Beneath the surface of society, signs of major change can be felt.