Where does “fiærþi” come from?

fiærþi (Old Swedish) comes from Old Norse fjórði, from Proto-Germanic fedurþô — fourth.

Ancestry of “fiærþi”, step by step

StepLanguageWordMeaning
1Old Norsefjórðifourth
2Proto-Germanicfedurþôfourth
Every word from Proto-Germanic fedurþô →Every word from Old Norse fjórði →