coffee mill noun2 •A device designed for grinding coffee beans.The best way to do the grinding is in an electric coffee mill, if you happen to have one, but the old mortar-and-pestle routine works well, too. — 1998 •A mill at which coffee beans are dried, roasted, and ground prior to sale.A good road leads to Pohoiki, once the site of a coffee mill and a prosperous village, but now almost deserted. — 1985 formscoffee mills · coffee-mills