Is foreign a proper noun

Answer 1

No, foreign is an adjective, a word that describes a noun. The noun form for the adjective is foreignness, a word for something alien, exotic, or strange. Another noun form is foreigner, a person who is from another place.

Both foreignness and foreigner are common nouns.

Answer 2

Oh, dude, "foreign" is not a proper noun. It's just an adjective used to describe something that comes from Another Country. Like, if you're talking about "Foreign Affairs" or "Foreign Films," you're just talking about stuff from outside your own borders. So yeah, it's not like a special name or anything, just a regular ol' word.