Águeda

Also Galician: https://gl.wikipedia.org/wiki/Lista_de_nomes_femininos_en_galego#I
http://www.ige.eu/igebdt/esq.jsp?idioma=gl&ruta=onomast/nomes.jsp

Also Portuguese. [noted -ed] Pronounced AH-ghə-duh.

You've never heard of it before because it is completely dated. At least in Spain, this is the name for an old lady living in a village so nobody is naming their daughter Agueda anymore.