Roumanian vs Rumanian

Roumanian is not a noun while Rumanian is a noun.

Word	Noun	Adjective	Verb	Adverb
Roumanian	No	Yes	No	No
Rumanian	Yes	Yes	No	No

As adjectives, Roumanian and Rumanian are synonyms defined as:

Roumanian and Rumanian: of or relating to or characteristic of the country of Romania or its people or languages

Other synonyms of Roumanian include Romanian.

Roumanian (noun)	Rumanian (noun)
	an eastern Romance language spoken in Romania
	a native or inhabitant of Romania

Roumanian (adjective)	Rumanian (adjective)
of or relating to or characteristic of the country of Romania or its people or languages	of or relating to or characteristic of the country of Romania or its people or languages