This is another, more expansive term for Arda as the kingdom of Manwë, including the World (Ambar), Aman and the Solar System (PE17/105). Its second element seems to be a variant of aranië “kingdom”, which appears in Tolkien’s translation of the Lord’s Prayer: Átaremma (VT43/12, 15).
Reference ✧ PE17/105 ✧ Ardaranye “Kingdom of Arda”
Related
ambar “the Earth” is apparently often used as an equivalent of Ardaranye “Kingdom of Arda” ✧ PE17/105