瞬しゅん膜まく

noun

nictitating membrane; haw

A transparent or translucent third eyelid present in some animals, used to protect and moisten the eye while maintaining vision. Technical term used in zoology.

• 鳥ちょう類るいや爬は虫ちゅう類るいには瞬しゅん膜まくがある。

  Birds and reptiles have a nictitating membrane.

• ワニが水すい中ちゅうで瞬しゅん膜まくを閉とじる。

  The crocodile closes its nictitating membrane underwater.