'Unclean' in the Bible

And in the synagogue there was a man, that had a spirit of an unclean demon; and he cried out with a loud voice,

And amazement came upon all, and they spake together, one with another, saying, What is this word? for with authority and power he commandeth the unclean spirits, and they come out.

and they that were troubled with unclean spirits were healed.

For he was commanding the unclean spirit to come out from the man. For oftentimes it had seized him: and he was kept under guard, and bound with chains and fetters; and breaking the bands asunder, he was driven of the demon into the deserts.

And as he was yet a coming, the demon dashed him down, and tare him grievously. But Jesus rebuked the unclean spirit, and healed the boy, and gave him back to his father.

The unclean spirit when he is gone out of the man, passeth through waterless places, seeking rest, and finding none, he saith, I will turn back unto my house whence I came out.