Save Gender Masculine Usage History (Ecclesiastical), Old Irish Pronounced Pron. /ˈmˠɪɾʲ.ˌxuː/(Old Irish) [key·simplify] Meaning & History Means "sea hound, sea wolf" in Old Irish, from Old Irish muir "sea" and cú "dog, hound, wolf". Muirchú moccu Machtheni was a monk and historian from Leinster who wrote the Vita sancti Patricii or The Life of Saint Patrick.