I would say they are the antonym of the definition of their name.

Hebrew, "טָהוֹר" (tahor) means "clean" or "pure," used in a physical, ceremonial, moral, or spiritual sense within the context of the Hebrew Bible. It is associated with ritual purity, moral integrity, and holiness, as seen in passages describing clean animals, pure offerings, and a pure heart. The word is derived from the root "טָהֵר" (taher), meaning "to cleanse". In Hebrew, the word lev (pronounced just as it is spelled) means heart, but not just the one that beats inside your chest. In the Bible, your lev is the very center of who you are.