Storbritannia.

From stor (“great”) + Britannia (“Britain”), literally “Great Britain”, after Latin Britannia Maior (“Great Britain”). The name distinguished the island from Britannia Minor (“Lesser Britain”), namely Bretagne (“Brittany”). The second element is from Latin Britannia (“Britain”). The Latin name, attested from the first century BCE, derives directly or through Ancient Greek Βρεττανία (Brettanía, “Britain”) and Πρεττανία (Prettanía, “Britain”). The Greek forms ultimately reflect a Celtic ethnonym conventionally reconstructed as early Proto-Brythonic *Pritanī, perhaps from Proto-Celtic *Kʷritanī or Proto-Celtic *Kʷritenī. A further connection with Proto-Indo-European *kʷer- (“to do”) has been proposed but remains uncertain. Parallel formations include Norwegian Nynorsk Storbritannia, Faroese Stórabretland, Icelandic Stóra-Bretland, Danish Storbritannien, Swedish Storbritannien, German Großbritannien, Dutch Groot-Brittannië, Finnish Iso-Britannia, Estonian Suurbritannia and English Great Britain.