[Facts] Re: Runeard (from Frozen 2)
I am pretty sure that this name was made up for the film, a search
"runeard" -frozen -arendell site:wikipedia.org
reveals essentially nothing, so no notable Runeards can be found outside the film.
For a meaning, you can retrofit some Germanic name elements, the first part is clearly "rune", the second one can also be "hard" instead of earth (which is not a frequent deuterotheme in Germanic names, and is of feminine grammatical gender in German, thus unfitting for a male).
--elbowin