Abbreviated slightly from Photius s.v. ('she who is working wool for a wage').
See generally LSJ s.v. e)/riqos, a noun which can be either masculine or feminine. In the present instance, as the gloss shows, it is the latter, and thus probably generated by Hesiod, Works and Days 602-3 ("I bid you look for a childless erithos; an erithos with an infant at the breast is a difficulty"). See also e.g. Demosthenes 57.45.