Norse vs Norwegian

Norse and Norwegian both are nouns.

Word	Noun	Adjective	Verb	Adverb
Norse	Yes	Yes	No	No
Norwegian	Yes	Yes	No	No

As adjectives, Norse and Norwegian are synonyms defined as:

Norse and Norwegian: of or relating to Norway or its people or culture or language

As nouns, Norwegian is a hyponym of Norse; that is, Norwegian is a word with a more specific, narrower meaning than Norse:

Norse: the northern family of Germanic languages that are spoken in Scandinavia and Iceland
Norwegian: a Scandinavian language that is spoken in Norway

As nouns, Norse and Norwegian are synonyms defined as:

Other synonyms of Norse include Norseman.

Norse (noun)	Norwegian (noun)
the northern family of Germanic languages that are spoken in Scandinavia and Iceland	a Scandinavian language that is spoken in Norway
a native or inhabitant of Norway	a native or inhabitant of Norway
an inhabitant of Scandinavia

Norse (adjective)	Norwegian (adjective)
of or relating to Norway or its people or culture or language	of or relating to Norway or its people or culture or language
of or relating to Scandinavia or its peoples or cultures