כותים – referring to the nations that were exiled to the Land of Israel by the kings of Assyria who were interested in populating the land after they had removed the Israelite people from it. The name derives from the ancient city of Kutha (in modern-day Iraq). According to II, chapter 17, these nations converted to Judaism because of their fear of lions that had begun attacking them (from which derives the term gerei arayot – “lion converts”), but they continued worshiping their gods at the same time.
Upon the return of the Jews to Israel at the beginning of the Second Temple period, the Samaritans, decedents of the Kutim, were active in trying to keep the returnees from rebuilding the Temple and the walls of the city of Jerusalem. Even so, there were families – including members of the kohanim – who intermarried with the Samaritans.