Portuguese vs European

Portuguese and European both are nouns.

Word	Noun	Adjective	Verb	Adverb
Portuguese	Yes	Yes	No	No
European	Yes	Yes	No	No

As nouns, European is a hypernym of Portuguese; that is, European is a word with a broader meaning than Portuguese:

Portuguese (noun)	European (noun)
the Romance language spoken in Portugal and Brazil	a native or inhabitant of Europe
a native or inhabitant of Portugal

Portuguese (adjective)	European (adjective)
of or relating to or characteristic of Portugal or the people of Portugal or their language	of or relating to or characteristic of Europe or the people of Europe