Save Type Surname (from given name) Usage Irish Pronounced Pron. KAG-nee [key] Other Forms FormsÓ Caingnigh, Ó Caingne Meaning & History Anglicized form of Irish Gaelic Ó Caingnigh meaning "descendant of Caingneach", a given name meaning "pleader, advocate". A famous bearer was American actor and dancer James Cagney (1899-1986).