noun
leatherback turtle
A species of sea turtle (Dermochelys coriacea). The name is usually written in katakana.
オサガメは世界最大の海亀です。
The leatherback turtle is the largest sea turtle in the world.
オサガメは絶滅危惧種に指定されています。
The leatherback turtle is designated as an endangered species.
The name likely derives from the leathery texture of its shell, with おさ (osa) possibly related to 瘡 (kasa, 'skin disease') or an old word for 'leather', and がめ (game) meaning 'turtle'. The exact origin is uncertain.