nictitating membrane
/ˈnɪktɪteɪtɪŋ/noun
- Zoology a whitish or translucent membrane that forms an inner eyelid in birds, reptiles, and some mammals. It can be drawn across the eye to protect it from dust and keep it moist.【动】（鸟、爬行动物和一些哺乳动物的）瞬膜。亦称THIRD EYELID.
词源
early 18th cent.: nictitating based on medieval Latin nictitat- 'blinked', frequentative of nictare.