unclean Syllabification: (un·clean)Pronunciation: /ˌənˈklēn/Translate unclean | into Spanish Definition of unclean adjective dirty:the company was fined for operating in unclean premises morally wrong:unclean thoughts (of food) regarded in a particular religion as impure and unfit to be eaten:pork is an unclean meat for Muslims (in biblical use) ritually impure; (of a spirit) evil. Derivatives uncleanness noun Origin: Old English unclǣne (see un-1, clean)unclean in other Oxford dictionaries Definition of unclean in the British & World English dictionary