nanna vs grandmother

nanna and grandmother both are nouns.

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

As nouns, nanna and grandmother are synonyms defined as:

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

nanna (noun)	grandmother (noun)
the mother of your father or mother	the mother of your father or mother