Nictitating

Part of speech: verb

Definitions

1. The movement of eyelids that ensures the eye stays hydrated while also providing a shield against potential irritants is essential for visual health
2. The action of drawing across the eye a thin, transparent membrane to protect and moisten it without fully closing the eye
3. The involuntary or voluntary sweeping motion of a semi-transparent eyelid that shields the eye and helps maintain moisture

Etymology: "Nictitating" comes from the Latin verb "nictare," meaning "to wink," which gave English "nictate" (to blink or wink). The Latin verb "nictitare" is a frequentative form of "nictare," meaning it expresses repeated or habitual action: to wink again and again. The English adjective and verb built on that participle stem describe the rapid, repeated closing of a membrane over the eye. The sense of the word is therefore tightly tied to its original Latin meaning of winking. What makes the term distinctive is that it describes a third eyelid, the nictitating membrane, which many birds, reptiles and some mammals possess. Its use in English reflects a scientific need for a precise term for an eyelid that moves sideways across the eye rather than up and down like a human lid.

Synonyms: blinking, winking