Meaning A boy's name of Celtic origin, it means "From Arthurian legend." Origin of Caswallan Celtic , Irish +-100%Zoom level changed to 1 Popular Middle Names Pronunciation 🔊 Listen Caswallan Similar Names Cassivellaunus Gwalchmai Guiomar Perce Cian Fergus Annan Artek Atre Arto Year by Year Popularity of Caswallan