Dachonna is a very common name in the list of saints, either as Conna and Connan, or with the prefixes of veneration Da or Do and Mo. It was the baptismal name of St. Machar (q.v.).
The most famous saint of this name is commemorated May 15. He was bishop of Connor, and of the race of Eoghan, son of Niall. "St. Dachonna the pious, bishop of Condere," died in 726.