Late 17th century: from Latin nictat- 'blinked', from the verb nictare. The variant nictitate is from the medieval Latin frequentative of nictare.
Definition of nictate in US English:
nictate
(also nictitate)
verbˈniktāt
[no object]rare
Blink.
the lid of her left eye began to nictate
Origin
Late 17th century: from Latin nictat- ‘blinked’, from the verb nictare ‘to blink’. The variant nictitate is from the medieval Latin frequentative of nictare.