'Unclean' in the Bible

I am using words in the way of men, because your flesh is feeble: as you gave your bodies as servants to what is unclean, and to evil to do evil, so now give them as servants to righteousness to do what is holy.

With right behaviour as in the day; not in pleasure-making and drinking, not in bad company and unclean behaviour, not in fighting and envy.

I know, and am persuaded by the Lord Jesus, that there is nothing unclean of itself: but to him that esteemeth any thing to be unclean, to him it is unclean.