rare: Down, Dublin. See Higgins. Also possibly English, cognate with Hicks, q.v.
Very numerous: all areas especially Connacht and Ulster. Ir. Ó h-Uiginn, uiging, a viking or sea-rover. A branch of the Southern Uí Néill, they moved to Connacht; a literary family noted for their poetic ability, they were later prominent in S America. IF & SGG.
fairly numerous: Galway-Mayo, N Leinster etc. Ir. Ó h-Uiginn, ? Viking. They were a sept of the Southern Uí Néill in W Meath, they were displaced to Sligo but flourished as a literary family. The name was notable in Spain and S America. IF.