'Unclean' in the Bible

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

And amazement came upon [them] all, and they began to talk with one another, saying, "What word [is] this? For he commands the unclean spirits with authority and power, and they come out!"

who came to hear him and to be healed of their diseases, and those who were troubled by unclean spirits were cured.

For he had commanded the unclean spirit to come out of the man. (For it had seized him many times, and he was bound with chains and shackles [and] was guarded, and breaking the bonds he would be driven by the demon into the deserted places.)

And [while] he was still approaching, the demon threw him down and convulsed [him]. But Jesus rebuked the unclean spirit and healed the boy, and gave him back to his father.

"Whenever an unclean spirit has gone out of a person, it travels through waterless places searching for rest, and does not find [it]. It says, 'I will return to my house from which I came out.'