noun
marginal sea; inland sea; epicontinental sea
Geographical term for a sea partly enclosed by islands, archipelagos, or peninsulas, adjacent to a wider ocean. Inland seas like the Seto Inland Sea and marginal seas like the Sea of Japan are also used. Technical synonyms 'epicontinental sea' and 'epeiric sea' refer to shallow seas over continental crust.
瀬戸内海は代表的な縁海である。
The Seto Inland Sea is a typical marginal sea.
縁海は大陸と海洋の境界に位置することが多い。
Marginal seas are often located at the boundary between continents and oceans.
Compound of 縁 (en, 'edge, margin') and 海 (kai, 'sea'). The term is a modern geographical coinage, likely calqued from Western geographical terminology.