fluidization(A roasting process in which finely divided solids are suspended in a rising current of air (or other fluid), producing a fluidized bed; used in the calcination of various materials, in the coal industry, etc.)
fluoridation(The addition of the fluorine ion to municipal water supplies in a final concentration of 0.8-1.6 ppm (parts per million) to help prevent dental caries in children, addition of fluor(ide, ions) to (drinking) water)
fluorine(A gaseous or liquid chemical element; a member of the halide family, it is the most electronegative element and the most chemically energetic of the nonmetallic elements; highly toxic, corrosive, and flammable; used in rocket fuels and as a chemical intermediate)