palpebration vs nictitation

palpebration and nictitation both are nouns.

Word	Noun	Adjective	Verb	Adverb
palpebration	Yes	No	No	No
nictitation	Yes	No	No	No

As nouns, nictitation is a hypernym of palpebration; that is, nictitation is a word with a broader meaning than palpebration:

palpebration: repeated blinking or winking (especially if uncontrolled and persistent)
nictitation: a reflex that closes and opens the eyes rapidly

Other hypernyms of palpebration include blink, blinking, eye blink, nictation, wink, winking.

palpebration (noun)	nictitation (noun)
repeated blinking or winking (especially if uncontrolled and persistent)	a reflex that closes and opens the eyes rapidly