Éire (Irish: [ˈeːɾʲə]) is Irish for "Ireland", the name of an island and a sovereign state. The English pronunciation is /ˈɛərə/ (AIR-ə).
The modern Irish Éire evolved from the Old Irish word Ériu, which was the name of a Gaelic goddess. Ériu is generally believed to have been the matron goddess of Ireland, a goddess of sovereignty, or simply a goddess of the land. The origin of Ériu has been traced to the Proto-Celtic reconstruction *Φīwerjon- (nominative singular Φīwerjū < Pre-Proto-Celtic -jō). This suggests a descent from the Proto-Indo-European reconstruction *piHwerjon-, likely related to the adjectival stem *piHwer- (cf. Sanskrit pīvan, pīvarī and pīvara meaning "fat, full, abounding"). This would suggest a meaning of "abundant land".
This Proto-Celtic form became Īweriū or Īveriū in Proto-Goidelic. It is highly likely that explorers borrowed and modified this term. During his exploration of northwest Europe (circa 320 BC), Pytheas of Massilia called the island Ierne (written Ἰέρνη). In his book Geographia (circa 150 AD), Claudius Ptolemaeus called the island Iouernia (written Ἰουερνία). Based on these historical accounts, the Roman Empire called the island Hibernia.