grandmother vs nanna

grandmother and nanna both are nouns.

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

As nouns, grandmother and nanna are synonyms defined as:

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

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