The Etymology of Ireland
Ireland is one of the oldest continuously used place-names in Europe. The native form Ériu (genitive Érenn) appears in early medieval Irish texts as both an island and a tutelary goddess. Linguists reconstruct the name through Proto-Celtic *Īwerjon- back to a Proto-Indo-European root *peyH- meaning to be fat or fertile — a reading that, while widely accepted, remains partly disputed because of irregular sound changes. Old English speakers compounded the borrowed Iras (the Irish people) with land to produce Iraland by around 1000 AD, and the modern spelling Ireland settled in the late medieval period. Latin writers preferred Hibernia, an unrelated reshaping influenced by hibernus (wintry). The Irish constitution of 1937 reinstated Éire as the official native form, so the country today carries two ancient names side by side — one Celtic, one Germanic, both pointing at the same green island.