2: Ciarán Ó Dubhghaill -New Name (NP)

<Ciarán >Given name found in "Index of Names in Irish Annals." by Kathleen M. O'Brien. Version 2.2, updated 24 August 2007

https://medievalscotland.org/kmo/AnnalsIndex/Masculine/Ciaran.shtml

Middle Irish Gaelic (c900-c1200) nominative form ranging from 512 to 1061 found 10 times.

<O Dubhghaill> Dubhghaill is the genitive form Early Modern Irish Gaelic (c1200-1700) found 980, 1268

Found via "Index of Names in Irish Annals." by Kathleen M. O'Brien. Version 2.2, updated 24 August 2007

http://medievalscotland.org/kmo/AnnalsIndex/Masculine/Dubgall.shtml

Clan affiliation by name is structured

The standard way to form a name using an Irish clan affiliation byname for men is: <single given name> Ó «eponvmous clan ancestor's name (in genitive case)

"Quick and Easy Gaelic Names" by Sharon L. Krossa htto://medievalscotland.org/scotnames/quickgaelicbynames/#clanaffiliationbyname