fluor (n.) Look up fluor at Dictionary.com
1660s, an old chemistry term for "minerals which were readily fusible and useful as fluxes in smelting" [Flood], from Latin fluor, originally meaning "a flowing, flow" (see fluent), said to be from a translation of the German miners' name, flusse. Since 1771 applied to minerals containing fluorine, especially calcium fluoride (fluorspar or fluorite).