The only reliable source for spelling and meaning of Basque names (and for legit Basque names) is Euskaltzaindia (the Academy of the Basque Language):
http://www.euskaltzaindia.com/eoda/index.asp?hizkuntza=es&onoma=izenak. The explanations are only available in Basque and in Spanish.
Naroa is a feminine name coming from the adjective
naroa, "abundant, plentiful", that in the coast of Gipuzkoa is equivalent to
lasai, "tranquil, quiet, peaceful". It has been often used as given name in the last years.
Lumia
http://onomastica.mailcatala.com