internuncio vs diplomatist

internuncio and diplomatist both are nouns.

Word	Noun	Adjective	Verb	Adverb
internuncio	Yes	No	No	No
diplomatist	Yes	No	No	No

As nouns, diplomatist is a hypernym of internuncio; that is, diplomatist is a word with a broader meaning than internuncio:

internuncio: (Roman Catholic Church) a diplomatic representative of the Pope ranking below a nuncio
diplomatist: an official engaged in international negotiations

Other hypernyms of internuncio include diplomat.

internuncio (noun)	diplomatist (noun)
(Roman Catholic Church) a diplomatic representative of the Pope ranking below a nuncio	an official engaged in international negotiations