Synonyms for Disreputable (same or very similar meaning)
WordNet sense 1 (morally degraded):
sordidWordNet sense 2 (of questionable taste or morality):
shadyWordNet sense 3 (having an exceedingly bad reputation):
infamous, notoriousWordNet sense 4 (tending to bring discredit or disrepute; blameworthy):
discreditableFrom the ODE community, based on WordNetadd/edit