Word of the Day:

: wink

Timothy developed a tic in his eyelid that caused it to nictitate on occasion.

"Their clear eyelids slowly nictitated over black orb eyes." -- From Barb and J.C. Hendee's 2011 novel Through Stone and Sea

"Nictitate" didn't just happen in the blink of an eye; it developed over time as an alteration of the older verb "nictate," which also means "to wink." Both verbs trace to the Latin word for winking, "nictare." The addition of the extra syllable was apparently influenced by Latin verbs ending in "-itare," such as "palpitare" and "agitare" (which gave us "palpitate" and "agitate," respectively). Today, "nictitate" has a special use in the animal world. Since the early 18th century, scientists have used "nictitating membrane" to describe the so-called "third eyelid": the thin, usually transparent membrane in the eyes of birds, fishes, and other vertebrates that helps keep the eyeball moist and clean.