Technical Term for Closing One's Eyelids

This page is the CodyCross answer for the clue below from Architectural Styles, Group 1166, Puzzle 4 (Parabolic Arch).

Question is: Technical Term for Closing One's Eyelids

and the answer is: NICTATE

Word Meaning:

NICTATE — (intransitive) To wink or blink; (of certain animals) to close the nictating membrane.

Definitions from Wiktionary.