Thule vs ultima Thule

Thule and ultima Thule both are nouns.

Word	Noun	Adjective	Verb	Adverb
Thule	Yes	No	No	No
ultima Thule	Yes	No	No	No

As nouns, Thule and ultima Thule are synonyms defined as:

Thule and ultima Thule: the geographical region believed by ancient geographers to be the northernmost land in the inhabited world

Thule (noun)	ultima Thule (noun)
the geographical region believed by ancient geographers to be the northernmost land in the inhabited world	the geographical region believed by ancient geographers to be the northernmost land in the inhabited world
a town in northwestern Greenland; during World War II a United States naval base was built there