I think the names Keady, Kedey, Cady, has as its Gaelic translation, the form: O'Ceidigh. (phonetically: O Kay Dee)The name Keady, Cady or O Ceidigh is not exactly the most common names in Ireland.
My ancestors are both O'Ceidigh and Keady. I was born Keady in Galway the west of Ireland. My father was born Keady in Dublin in the east of Ireland. My Grandfather born Keady in Cork in the south of Ireland. My Great Grandfather born O'Ceidigh from Spiddal, Connemara Co Galway.