What land mass or island was known in antiquity as "Hibernia"?

Hibernia is the Classical Latin name for the island of Ireland, which is comprised of the modern countries of Ireland and Northern Ireland. The name Hibernia was taken from Greek geographical accounts. During his exploration of northwest Europe (c. 320 BC), Pytheas of Massilia called the island Iérnē (written Ἰέρνη). In his book Geographia (c. 150 AD), Claudius Ptolemaeus ("Ptolemy") called the island Iouerníā (written Ἰουερνία, where "ου"-ou stands for w). The Roman historian Tacitus, in his book Agricola (c. 98 AD), uses the name Hibernia. The Romans also sometimes used Scotia, "land of the Scoti", as a geographical term for Ireland in general, as well as just the part inhabited by those people.

Ιουέρνια (Iouerníā) was a Greek rendering of the Celtic name *Īweriū from which eventually arose the Irish names Ériu and Éire. The original meaning of the name is thought to be "land of winter".

Geographically, the island of Ireland is the 3rd-largest in Europe, while its neighboring island, Great Britain is the largest island in Europe. The island of Great Britain is comprised of England, Scotland, and Wales.