Synonyms for Bastardly (same or very similar meaning)
WordNet sense 1 (born out of wedlock):
misbegotten, spurious, misbegotWordNet sense 2 (of marriages and offspring; not recognized as lawful):
illegitimateWordNet sense 3 (of no value or worth):
meanWordNet sense 4 (deserving of contempt or scorn):
contemptibleFrom the ODE community, based on WordNetadd/edit