Lusitania vs Lusitanian

Lusitania is a noun but Lusitanian is not a noun.

Word	Noun	Adjective	Verb	Adverb
Lusitania	Yes	No	No	No
Lusitanian	No	Yes	No	No

Lusitania (noun)	Lusitanian (noun)
ancient region and Roman province on the Iberian Peninsula; corresponds roughly to modern Portugal and parts of Spain

Lusitania (adjective)	Lusitanian (adjective)
	of or relating to or characteristic of the region of Lusitania or its people or language
	of or relating to or characteristic of Portugal or the people of Portugal or their language