I have a Lurancy in my family tree, who was born in 1798. I suspect it is an American creation, possibly based on Laurence/Lorenzo or Laura and Nancy. I've seen other created names like Isannah, Martitia, etc.
Several websites have the meaning of Eryl as "lookout" or "watcher", but I don't know how accurate that is. Here's one:
http://www.namenerds.com/welsh/trad1.html