Combustion or burning, in which substances combine chemically with oxygen from the air and typically give out bright light, heat, and smoke. The shooting of projectiles from weapons, especially bullets from guns. Discharge a gun or other weapon in order to explosively propel (a bullet or projectile). Dismiss (an employee) from a job. Supply (a furnace, engine, boiler, or power station) with fuel. Stimulate or excite (the imagination or an emotion). Bake or dry (pottery, bricks, etc.) in a kiln. Start (an engine or other device).