Internuncio
Internuncio , noun
[Latin internuntius; inter between + nuntius, nuncius, messenger: compare Italian internunzio. See Nuncio.]
1.
A messenger between two parties. — Johnson
2.
A representative, or chargé d'affaires, of the pope at a foreign court or seat of government, ranking next below a nuncio.
This title was formerly given also to the Austrian envoy at Constantinople.