dead calm

Adjective

not-comparable of a body of water

(of a body of water) Completely still with no waves and no wind.

Japanese Meaning

全く風も波もなく、完全に静まり返った状態。 / 海や湖などで、風がなく、波が立たない静寂な様子。

The sea was dead calm as we set out at dawn.

夜明けに出航したとき、海は波も風もなく凪いでいた。

Sense（1）

(of a body of water) Completely still with no waves and no wind.

We were drifting on a dead calm sea for a third week in a row.