The open sea; waters away from the shore or shallow areas — used in navigation, fishing, and weather contexts.
天気予報では今夜、沖は波が高くなるでしょうと言っていた。
The weather forecast said the waves will be high offshore tonight.
船は朝早く沖へ出た。
The boat went out to sea early in the morning.
沖釣りは岸からでは釣れない大物を狙う釣り方だ。
Offshore fishing targets big fish that can't be caught from the shore.
An abbreviation for Okinawa (沖縄) used in headlines or shorthand contexts.
手紙の地名欄に『沖』とだけ書かれていたので、沖縄のことだと分かった。
Only 'Oki' was written in the address field, so I understood it meant Okinawa.