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.
鳥類や爬虫類には瞬膜がある。
Birds and reptiles have a nictitating membrane.
ワニが水中で瞬膜を閉じる。
The crocodile closes its nictitating membrane underwater.