Synonyms for Squalid (same or very similar meaning)
WordNet sense 1 (morally degraded):
seamy, seedy, sleazy, sordidWordNet sense 2 (lacking respectability in character or behavior or appearance):
disreputableWordNet sense 3 (foul and run-down and repulsive):
flyblownWordNet sense 4 (soiled or likely to soil with dirt or grime):
dirty, soiledFrom the ODE community, based on WordNetadd/edit