A heater is a device used to warm up a space or an object. BOILER, KILN, ROSCOE, STOVE, ROD, OVEN, FURNACE, FASTBALL, GUN, GAT, RADIATOR, Etna, and PIECE are all terms related to heaters. A BOILER is a closed vessel in which water or other fluid is heated. A KILN is an OVEN or FURNACE used for burning, baking, or drying, especially one for firing pottery. ROSCOE is a slang term for a handgun. A STOVE is a device or structure for heating or cooking. A ROD is a long, thin, cylindrical object. An OVEN is a thermally insulated chamber used for the heating, baking, or drying of a substance. A FURNACE is a device used for heating. A FASTBALL is a type of pitch in baseball. A GUN is a weapon that fires bullets or projectiles. A GAT is a slang term for a GUN. A RADIATOR is a device used to transfer heat from one medium to another. Etna is a type of FURNACE. PIECE is a slang term for a GUN.