1. (n.) One who, or that which, heats.

2. (n.) Any contrivance or implement, as a furnace, stove, or other heated body or vessel, etc., used to impart heat to something, or to contain something to be heated.

Bunsen burner Dutch oven automatic bedpan bloom heater blowgun blowpipe brazier brick oven burner calefactory caliduct car heater cooker cookery defroster dielectric heater dielectric preheater electric blanket electric heater electronic heater element firearm fireless heater flamethrower foot warmer forge furnace gas jet gas log gat geyser gun handgun heat lamp heating duct high-frequency heater hot-water bag hot-water bottle hot-water heater induction heater infrared heater infrared lamp ingot heater iron heater jet kerosene heater kiln musket orchard heater oven peashooter piece pilot light pistol preheater radiator radio-frequency heater register repeater revolver rifle rod sawed-off shotgun shooting iron shotgun six-gun six-shooter steam pipe stove sun lamp tewel tuyere warmer