大洋|たいようtaiyou[0]heiban (flat)

1. no-adjectiveocean
   アメリカに行いくには大洋たいようを横断おうだんしなければなりません。↗

   You have to cross the ocean to get to America.

• Synonym海うみNeutralThe everyday word for the sea, most common and broadest in range. 「大洋」 is more written and points to a vast ocean, especially the great oceans like the Pacific.
• Synonym海洋かいようWrittenWritten word used in academic and formal contexts, as in 「海洋学」. 「大洋」 instead points to large ocean areas such as the five great oceans.
• SynonymオーシャンNeutralA loanword for the ocean or open sea, often used in names. 「大洋」 is a Sino-Japanese word.
• Synonym海原うなばらWrittenWritten and poetic, for a broad stretch of open sea. 「大洋」 is the geographical term.
• Synonym大海たいかいNeutralA vast sea; known from the proverb 「井の中の蛙大海を知らず」. 「大洋」 leans toward the geographical oceans.
• Related外洋がいようWrittenWritten word for the open sea far from land. 「大洋」 points to the ocean region as a whole.
• Related遠洋えんようWrittenWritten word for distant waters, as in 「遠洋漁業」. 「大洋」 refers to the ocean itself.
• Related遠海えんかいWrittenWritten word for waters far from land. 「大洋」 refers to the ocean itself.
• Related外海がいかいNeutralThe open sea not enclosed by land. 「大洋」 leans toward the five great oceans.
• Related大海原おおうなばらWrittenWritten and literary, for a boundless expanse of sea. 「大洋」 is more of a geographical term.

For the geographical oceans — the Pacific, the Atlantic — or a vast sea, use 「大洋」. In everyday speech say 「海」; in written or academic contexts 「海洋」; for literary pictures of the open sea 「大海原」 or 「海原」; for distant waters, as in fishing, 「遠洋」.

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

1. 大おおきくて広ひろい海うみ。大海たいかい。大海たいかい洋よう。独立どくりつ海かい。水圏すいけんの大部分だいぶぶんを占しめる、それぞれが接続せつぞくした地球ちきゅう上じょうの海うみの主要しゅよう領域りょういき。一般的いっぱんてきには、北極海ほっきょくかい・太平洋たいへいよう・大西洋たいせいよう・インド洋いんどよう・南極海なんきょくかいの5つに区分くぶんされる。オーシャン。