Firing \Fir"ing\, n. 1. The act of disharging firearms. 2. The mode of introducing fuel into the furnace and working it. --Knight. 3. The application of fire, or of a cautery. --Dunglison. 4. The process of partly vitrifying pottery by exposing it to intense heat in a kiln. 5. Fuel; firewood or coal. [Obs.] --Mortimer. {Firing iron}, an instrument used in cauterizing.