adjective (a)

• soiled or likely to soil with dirt or grime(adj.all)

  Example:
  Wore an unclean shirt.
  

  Synonym:
  dirty, soiled
  Antonym:
  clean
  

  source: wordnet30
• having a physical or moral blemish so as to make impure according to dietary or ceremonial laws(adj.all)

  Example:
  Unclean meat.
  And the swine...is unclean to you.
  

  Synonym:
  impure
  

  source: wordnet30
• Not clean; foul; dirty; filthy.(adjective)

  source: webster1913