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Glite Dictionary
nictitating membrane

nictitating membrane

1 9.9
A thin transparent third eyelid that protects and keeps the eye wet
  • noun
  • /ˈnɪktɪˌteɪtɪŋ ˈmɛmˌbreɪn/
  • Specialized
translation icon : membrana nictitante
  • Birds use their nictitating membranes to keep their eyes moist and shielded while hunting.
  • nictitating membrane, or third eyelid
  • nictitating membranes flickered
  • nictitating membrane across your eye

Examples

  • That question was answered when one of them came and 'smiled' for the camera, literally inches away from me, its protective nictitating membrane flickering across its eye, a reflex action when anything comes within 'touching' range of its incredible predatory maw.

    Blog text (7)

  • I see her eyes flicker, though the nictitating membrane closes as she does it.

    Fiction book (2001)

  • No noses, just broad flat nostrils with nictitating membranes.

    Fiction book (2000)

  • Later, O'Rourke had a real breakthrough when she discovered that prions collect in pockets of lymphoid tissue in a sheep's nictitating membrane, or third eyelid.

    Academic text (2004)

  • The hawk's nictitating membrane protects its eyes from debris while soaring through the sky.

  • When the alligator senses danger, its nictitating membrane covers its eyes for added protection.

Synonyms

third eyelid
vsnictitating membrane
  • Specialized
1 8.9

A thin clear layer that slides across the eye to protect it

is transparent and moistens the eye while still allowing visibility
haw
vsnictitating membrane
  • Specialized
9.9

A thin protective third eyelid in the inner corner of an eye

is transparent and moistens the eye while still allowing visibility

Surface Forms

nictitating membrane singular
nictitating membranes plural

Morphology

nictitating + membrane

The phrase is compositional: 'nictitating' (performing a nictation or blinking action) combined with 'membrane' (a thin layer) yields a thin layer that blinks or closes over the eye. Although 'nictitating' is a technical/rare adjective, the adjective+noun structure is regular and a learner who knows both constituents can infer it refers to the protective third eyelid described in the definition.

Etymology

Nictitating membrane: The term nictitating membrane comes from a word meaning 'to wink'; the clear membrane is a thin third eyelid that sweeps across the eye like a quick blink. That's why the phrase means the thin, protective eyelid that moves to 'protect' and 'moisten' the eye while the animal can still see.