The Brittonic, Brythonic or British Celtic languages (ieithoedd Brythonaidd/Prydeinig, yethow brythonek/predennek, yezhoù predenek) form one of the two branches of the Insular Celtic language family; the other is Goidelic. The name Brythonic was derived by Welsh Celticist John Rhys from the Welsh word Brython, meaning an indigenous Briton as oppo...