Black, (Zeph. 1:4; rendered "idolatrous priests" in 2 Kings 23:5, and "priests" in Hos. 10:5). Some derive this word from the Assyrian Kamaru, meaning "to throw down," and interpret it as describing the idolatrous priests who prostrate themselves before the idols. Others regard it as meaning "those who go about in black," or "ascetics."
Easton's Bible Dictionary. M.G. Easton. 1897.