'Unclean Spirit' in the Bible

And I saw, and out of the mouth of the dragon, and out of the mouth of the beast, and out of the mouth of the false prophet there came forth three unclean spirits, like frogs:

And he cried with a mighty and a loud voice, saying, It is fallen! it is fallen! it is fallen! even Babylon the Great: and it is become the habitation of demons, and the hold of every unclean spirit, and a cage of every unclean and hateful bird: