'Unclean' in the Bible

And there was a man in the Synagogue who had an unclean spirit; and he gave a loud cry and said,

And those who were troubled with unclean spirits were made well.

And while he was coming, he was pushed violently down and twisted by the evil spirit. But Jesus gave sharp orders to the unclean spirit, and made the boy well, and gave him back to his father.

The unclean spirit, when he has gone out of a man, goes through dry places, looking for rest; and when he does not get it, he says, I will go back to my house from which I came.