Mac An Deagáin, Mac An Deagánaigh
Mac an DEAGÁIN, Mac an DEAGÁNAIGH—VII— M'Adegain, M'Adegany, M'Idegane, M'Idigany, M'Deane, MacDigany, Dagney, Digany, Digney, Deane, etc.; 'son of the dean,' (Irish 'deagán,' 'deagánach,' Latin 'decanus'). This surname was found in the 16th century in many parts of Ireland, but especially in Donegal, where the families so named seem to have been originally O'Donnells and O'Gallaghers. It is now very often translated Deane.
Alphabetical Index to Irish Surnames