Meaning of Corann. Celtic name. In Celtic, the name Corann means-Mythical druid.. Other origins for the name Corann include-Celtic, Irish.The name Corann is most often used as a boy name or male name.Celtic Name Meaning-Mythical druid.ther origins for the name Corann include-Celtic, Irish.The name Corann is most often used as a boy name or male name. Celtic Name Meaning-Mythical druid.