Etymology disputed. Compare Erdély, the Hungarian name for the region. While the names are clearly related, it is uncertain which language borrowed from which, or what the ultimate source is for the name. Possibly ultimately of Celtic origin, from a word ardal, meaning "country, land", as the region was occupied by Celts in antiquity. Alternatively from Hungarian Erdő-elve (“land beyond the forest”). The synonym Transilvania was later borrowed from Latin. See Historical names of Transylvania for more information.