nan vs nanna

nan and nanna both are nouns.

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

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

Other hypernyms of nan include gran, grandma, grandmother, grannie, granny, nan.

As nouns, nan and nanna are synonyms defined as:

Other synonyms of nan include gran, grandma, grandmother, grannie, granny.

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