Mag Fhionnáin
Mag FHIONNÁIN—IV—M'Gynnan, M'Gennan, M'Geanayne, MacGannon, Ginnane, Gannon; 'son of Fionnán' (diminutive of fionn, fair); the name of an ancient family, formerly of Erris, Co. Mayo, and still represented in that county.
Alphabetical Index to Irish Surnames