Thule \Thu"le\, n. [L. Thule, Thyle, Gr. ?, ?.]

The name given by ancient geographers to the northernmost part of the habitable world. According to some, this land was Norway, according to others, Iceland, or more probably Mainland, the largest of the Shetland islands; hence, the Latin phrase ultima Thule, farthest Thule.

Source: Webster's Revised Unabridged Dictionary (1913)