Found 2 items, similar to Nictitating membrane.
English → English (WordNet) Definition: nictitating membrane nictitating membrane n : a protective fold of skin in the eyes of reptiles and birds and some mammals [syn: third eyelid]
English → English (gcide) Definition: Nictitating membrane 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]