nan vs grandparent

nan and grandparent both are nouns.

Word	Noun	Adjective	Verb	Adverb
nan	Yes	No	No	No
grandparent	Yes	No	No	No

As nouns, grandparent is a hypernym of nan; that is, grandparent is a word with a broader meaning than nan:

nan (noun)	grandparent (noun)
leavened bread baked in a clay oven in India; usually shaped like a teardrop	a parent of your father or mother
your grandmother
the mother of your father or mother