nictitating membrane

noun

: a thin membrane found in many vertebrates at the inner angle or beneath the lower lid of the eye and capable of extending across the eyeball

Examples of nictitating membrane in a Sentence

Recent Examples on the Web

Other species guard their vision with a third eyelid called a nictitating membrane. —Gemma Tarlach, Discover Magazine, 19 Jan. 2016

In other animals, the nictitating membrane is a fold of tissue in the inner corner of the eye that serves as a sort of third eyelid, providing protection and cleaning. —Scott Lafee, San Diego Union-Tribune, 25 Oct. 2022

Word History

First Known Use

1713, in the meaning defined above

Kids Definition

nictitating membrane

noun

nic·​ti·​tat·​ing membrane

ˌnik-tə-ˌtāt-iŋ-

: a thin membrane found in many animals at the inner angle or beneath the lower lid of the eye and capable of extending across the eyeball

Medical Definition

nictitating membrane

noun

: a thin membrane found in many vertebrate animals at the inner angle or beneath the lower lid of the eye and capable of extending across the eyeball

called also membrana nictitans, third eyelid