My ancestor with the middle name Degian spelled it that way twice, in different voter registrations. So that is the way his family decided to spell it. They could all read and write; his father was a County Clerk as a young adult.
Most of the time he just went by his initials, N. D. Farris. However, the family names argue for Celtic origen: Dunbar (his mother's surname) and Farris; Pinnick for another grandparent.
I did a Google on Degian and came up with a linux program, and a few surnames Degian out there, at least one of which seems to be Hungarian!
So it's still a mystery, but the similarity to Degan, combined with the Celtic background, made me ask here.