'Nictitating membrane' definitions:
Definition of 'nictitating membrane'
(from WordNet)
noun
A protective fold of skin in the eyes of reptiles and birds and some mammals [syn: nictitating membrane, third eyelid]
Definition of 'Nictitating membrane'
From: GCIDE
- Nictitate \Nic"ti*tate\, v. i. [See Nictate.] To wink; to nictate. [1913 Webster]
- Nictitating membrane (Anat.), a thin membrane, found in many animals at the inner angle, or beneath the lower lid, of the eye, and capable of being drawn across the eyeball; the third eyelid; the haw. [1913 Webster]