Where does “Arpadia” come from?

Arpadia (Romanian) comes from Romanian Arpad, from Hungarian Árpád, from Hungarian árpa, from Proto-Turkic arpa, from Proto-Iranian arpacyaH, from Proto-Iranian Hr̥pā́š ~ Hr̥pacáh, from Proto-Indo-Iranian Hr̥pā́ćš ~ Hr̥paćás, from Proto-Indo-Iranian -ā́ćš.

Ancestry of “Arpadia”, step by step

StepLanguageWordMeaning
1RomanianArpad
2HungarianÁrpád
3Hungarianárpabarley; stye, hordeolum
4Proto-Turkicarpabarley
5Proto-IranianarpacyaHbarley
6Proto-IranianHr̥pā́š ~ Hr̥pacáh
7Proto-Indo-IranianHr̥pā́ćš ~ Hr̥paćás
8Proto-Indo-Iranian-ā́ćšanimal and plant suffix
9Proto-Indo-European-eḱés
Every word from Proto-Indo-European -eḱésEvery word from Proto-Indo-Iranian -ā́ćšEvery word from Proto-Indo-Iranian Hr̥pā́ćš ~ Hr̥paćás