浅瀨(あさせ)

shallows; shallow water

瀨戸(せと)

strait; narrow channel

瀨戸際(せとぎわ)

critical moment; brink

瀨音(せおと)

sound of rapids

急瀨(きゅうらい)

rapids; swift current

早瀨(はやせ)

swift current; rapids

荒瀨(あらせ)

rough rapids

瀨踏(せぶ)み

testing the waters; sounding out a situation

立(

会社(かいしゃ)は瀨戸際(せとぎわ)に追(お)い込(こ)まれた。

The company was driven to the brink.

渓流(けいりゅう)に耳(みみ)を澄(す)ますと、瀨音(せおと)がかすかに聞(き)こえた。

When I listened closely to the mountain stream, I could faintly hear the sound of the rapids.