Mac Giolla Ghuala
Mac GIOLLA GHUALA—IV—M'Gillegowly M'Gilgowlye, M'Kellogulie, Gillowly, Gillooly, Gilooly, Gilhooly, Killooley; 'son of Giolla ghuala' (glutton, Irish guala, Latin gula, gluttony); the name of a branch of the family of O'Mulvey in the east of Co. Leitrim, where it is still common. It has been corrupted to Mac Giolla shúiligh, which see.
Alphabetical Index to Irish Surnames