northernmost part of the world, Old English, from Latin, from Greek Thyle "land six days' sail north of Britain" (Polybius). Identity is speculative; it came to be used in a transferred sense of "extreme limits of travel."
in literature, the furthest possible place in the world. Thule was the northernmost part of the habitable ancient world. (See Thule culture.) References to ultima Thule in modern literature appear in works by Edgar Allan Poe, Henry Wadsworth Longfellow, and the Australian writer Henry Handel Richardson.