unclean 21 synonyms and 1 antonyms for unclean, ranked by how commonly they're used. Adj — Dirty or covered in filth. Synonyms for unclean befouled besmirched clarty cruddy dirtsome dirty foul grotty grubby horry icky lousy manky nasty soiled seamy sordid squalid sullied unwashed yucky Antonyms for unclean clean ← Back to the full definition of unclean