picklepuss vs persona non grata

picklepuss and persona non grata both are nouns.

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

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

Other hypernyms of picklepuss include unwelcome person.

picklepuss (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