cow shark
noun
1- a dull grey or brown shark that lives mainly in deep water, especially in the North Atlantic and Mediterranean（尤指生活在北大西洋和地中海的深水的）六鳃鲨。
1.1
- Hexanchus griseus, family Hexanchidae.拉丁名 Hexanchus griseus,六鳃鲨科。