Synonyms for Dud (same or very similar meaning)
WordNet sense 1 (someone who is unsuccessful):
flop, washoutWordNet sense 2 (an explosion that fails to occur):
misfireWordNet sense 3 (an event that fails badly or is totally ineffectual):
bomb, turkeyWordNet sense 4 ((of weapons) not charged with ammunition):
unloadedFrom the ODE community, based on WordNetadd/edit