sourpuss vs persona non grata

sourpuss and persona non grata both are nouns.

Word	Noun	Adjective	Verb	Adverb
sourpuss	Yes	No	No	No
persona non grata	Yes	No	No	No

As nouns, persona non grata is a hypernym of sourpuss; that is, persona non grata is a word with a broader meaning than sourpuss:

Other hypernyms of sourpuss include unwelcome person.

sourpuss (noun)	persona non grata (noun)
someone with a habitually sullen or gloomy expression	a person who for some reason is not wanted or welcome
	a diplomat who is unacceptable to the government to which he is sent