海獣(かいじゅう) かいじゅう noun marine mammal animal-mammal 1. marine mammal A mammal that lives primarily in the ocean, such as seals, sea lions, walruses, and sea otters. A zoological term. 水族館(すいぞくかん)で海獣(かいじゅう)のショーを見(み)た。🔊 I watched a marine mammal show at the aquarium. アザラシやセイウチは海獣(かいじゅう)に分類(ぶんるい)される。🔊 Seals and walruses are classified as marine mammals. 北海道(ほっかいどう)の海岸(かいがん)では野生(やせい)の海獣(かいじゅう)を観察(かんさつ)できることがある。🔊 On the coasts of Hokkaido, it is sometimes possible to observe wild marine mammals. 海(かい) (sea) + 獣(じゅう) (beast): mammals that live in the sea, not fish. A zoological word; in conversation people name the animal.Typesアザラシ: sealアシカ: sea lionセイウチ: walrusラッコ: sea otterクジラ / イルカ: whale / dolphin (sometimes included)Watch out怪獣(かいじゅう): monster (as in Godzilla); same reading general Added 2026.3.24 23:04 · Revised 2026.10.8 11:00 19000/19212_kaijuu