pouter vs persona non grata

pouter and persona non grata both are nouns.

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

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

Other hypernyms of pouter include unwelcome person.

pouter (noun)	persona non grata (noun)
one of a breed of pigeon that enlarge their crop until their breast is puffed out	a person who for some reason is not wanted or welcome
someone with a habitually sullen or gloomy expression	a diplomat who is unacceptable to the government to which he is sent