'Unclean' in the Bible

They made search for their record among the lists of families, but their names were nowhere to be seen; so they were looked on as unclean and no longer priests.

Which you gave to your servants the prophets, saying, The land into which you are going, to take it for a heritage, is an unclean land, because of the evil lives of the peoples of the land and their disgusting ways, which have made the land unclean from end to end.