海港|かいこうkaikou[0]heiban (flat)

1. nounport; seaport

• Synonym港みなとNeutralThe everyday word and the most common of all: it covers ports on lakes and rivers too, so its range is wider than 「海港」, which is only for ports on the sea.
• Synonym港津こうしんWrittenWritten word meaning simply port or harbour; very rare and almost only seen in prose, with a more archaic flavour than 「海港」.
• Related港みなとNeutralThe everyday word and the most common of all: it covers ports on lakes and rivers too, so its range is wider than 「海港」, which is only for ports on the sea.
• RelatedハーバーNeutralLoanword for a harbour or dock; mostly seen in 「ヨットハーバー」 and in facility or place names. For a plain statement about a seaside port, use 「港」 or 「海港」.
• Related港湾こうわんWrittenWritten, administrative and technical term for the port district with berthing and cargo-handling facilities, as in 「港湾施設」.

Say 「港」 in everyday speech; use 「海港」 to stress that the port is on the sea, as opposed to a river port. 「ハーバー」 fits yacht harbours and facility or place names, 「港湾」 administrative and technical prose; 「港津」 is rare literary.

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

1. 海岸かいがんにある港みなと。