外洋|がいようgaiyou[0]heiban (flat)

1. nounopen sea; ocean
   海うみの氷こおりはきわめて変かわりやすい――寒さむく風かぜのない天候てんこうのときは固かたく凍こおっているが、嵐あらしのときは外洋がいようの広ひろい水域すいいきで割われてしまう。↗

   The sea ice is highly variable - frozen solid during cold, calm weather and broken up in large areas of open water during storms.

• Synonym遠洋えんようNeutralThe sea far offshore, typically in 「遠洋漁業」; stresses distance for voyaging or fishing rather than openness.
• Synonym外海がいかいNeutralThe outer sea not enclosed by land; close in meaning to 「外洋」 and often paired with 「内海」.
• Related海洋かいようNeutralThe ocean as a whole; often academic, as in 「海洋資源」. Unlike 「外洋」, it says nothing about distance from shore.
• Related大洋たいようNeutralThe great oceans — Pacific, Atlantic and the rest; a geographical classification, vaster in scale than 「外洋」.
• Related海原うなばらWrittenA boundless expanse of sea; a literary native-Japanese word, common in poetry, that belongs to written prose.
• RelatedオーシャンNeutralLoanword for the ocean, used mostly in names and advertising copy, e.g. 「オーシャンビュー」.
• Related大海たいかいNeutralA broad, vast sea, as in the proverb 「井の中の蛙大海を知らず」; stresses sheer size rather than distance from land.
• Related遠海えんかいWrittenWaters far from land; written and rather rare — 「遠洋」 is the usual word.
• Related大海原おおうなばらWrittenA vast, boundless sea; a literary expression stressing immense, endless breadth, found in written prose.
• Antonym内海ないかいNeutralAntonym: a sea almost entirely enclosed by land, as in 「瀬戸内海」 — the opposite of the open 「外洋」.
• Antonym沿岸えんがんNeutralAntonym: waters close along the coast — the opposite of 「外洋」, which lies far from land.

Use 「外洋」 for the open sea far from land, as in 「外洋航海」. For distance in fishing or voyaging say 「遠洋」; for the ocean as a whole, 「海洋」. 「内海」 and 「沿岸」 are the opposites: enclosed and coastal waters.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 陸地りくちから遠とおく離はなれた、広々ひろびろとした海うみ。