Nanna is only slang for grandmother in English-speaking countries. In Sweden and Norway grandmother is called "Mormor/Farmor" and the most common slang is Mommo or Fammo. It has nothing to do with grandmothers where it's used.
― Anonymous User 1/2/2019
6
Nanna Bryndis Hilmarsdottir - Great singer In the band Of Monsters and Men. She is Icelandic. Pronounced- NON-NUH.
Seeing that Nanna is a perfectly normal name in many languages - and is a goddess in Norse mythology even! - and as 'nana' is a petform/slang for grandmother in English speaking countries only, I find the grandmother comment above somewhat stupid and ignorant.
― Anonymous User 5/27/2010
10
I think Nanna is a lovely nickname, but I would be unsure about putting it on a birth certificate, because some people call their grandmothers "Nanna". I like how this name originates in mythology, and it's cute that "Nanna" is a word for "sweets" in Finnish. For me, that's a positive association. Nanna certainly does sound very sweet and youthful, almost childlike. I think I would use it as a nickname for Inanna.
― Anonymous User 2/12/2010
5
A very child-like, cutesy name that no one can be taken very seriously with.
Sources: https://www.stat.ee/public/apps/nimed/
https://fi.m.wikipedia.org/wiki/Nanna_(nimi)
https://almanakka.helsinki.fi/en/name-days/name-day-search.html
https://forebears.io/forenames/nanna (I think)