I thought that it could be a mistake for bastardizing, perhaps for the feminine of 'bastero' or 'bardero', but I thought about it a little more and it occurred to me that perhaps it does exist as a feminine of some gentilicio, as for the locality of Bastardero (Leonardo Infante municipality, state of Guárico, Venezuela), or for the parish Fonte do Bastardo (municipality of Praia da Vitória, Terceira Island, Autonomous Region of the Azores, Portugal), although 'bastardense' is used here. See wachupa.
